Workplace Hazard Notes of IGC 2

NEBOSH National General Certificate TOPICS OF (CONTROLLING WORKPLACE HAZARDS)

Safety Signs Personal Protective Equipment Manual Handling Mechanical Handling & Transport Safety Work Equipment Maintenance Electrical Safety Fire Chemical Hazards Occupational Ventilation Health Hazards Ergonomics Noise Radiation Construction, Demolition, & Excavation Working Above Ground Level Waste

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NEBOSH National General Certificate SAFETY SIGNS Exercise1 State the shape and colors of the following types of safety signs and give example of each: • • • •

Prohibition Warning Mandatory Safe condition

Answer 1

The sign

Shape

Color

Prohibition WarninQ Mandatory

Circular TrianQular Circular

White Yellow Blue

Safe condition

Rectangular

Green

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Example No smoking Toxic substance Hearing protection mandatory First aid

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NEBOSH National General Certificate PERSONAL

PROTECTIVE

EQUIPMENT

Exercise 1 Outline the factors to be considered in the selection of eye protection for use at work. Answer 1 • • • • • • •

Type and nature of the hazard (impact, chemical splash, UV light, etc). Type & standard of protection. Comfort & user acceptability. Compatibility with other items. Maintenance requirements. Costs. Training requirements.

Exercise 2 Identify one advantage and one disadvantage of safety goggles compared with safety spectacles. Answer 2 • •

Advantage of safety goggles over safety spectacles is: all around protection. Disadvantage of safety goggle: is the tendency to mist.

Exercise 3 Explain the different between breathing apparatus and respirator. Answer 3 Respirator: is a filter for removal of air contaminants. It is either half or full face respirator and it includes a cartridge specific for the type of air contaminant e.g.: dust, vapor, fume, etc. Breathing apparatus: is an apparatus supplying the wearer with clean air or oxygen to help breathing when present in hostile atmospheres (of very low oxygen levels or contaminated with high toxicity contaminants). It is either: fresh air hose apparatus, compressed airline apparatus or self contained breathing apparatus (SCBA). Exercise 4 Outline the main limitations of a half-mask re-useable respirator. Answer 4 • • • • •

The filter selection. Limited levels of protection. Ergonomic considerations (comfort, fit, etc.). Incompatibility with other equipment. Limitations in oxygen deficient atmosphere.

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NEBOSH National General Certificate Identify FOUR limitations of personal hearing protection as a means of protection against the effects of noise. Answer 5 • • • • • • • •

Poor fit. Resistance to use. Uncomfortably Incompatibility with other equipment Cost of maintenance & replacement. Hygiene problems. Need for continuous supervision. Communication problems

Exercise 6 Outline the factors to be considered in the selection and use of personal head protection at work. Answer 6 • • • • • • • • •

Type of risk (falling objects, impact, entanglement, etc.) The level of protection to be afforded. Compliance with standards. Ergonomic factors (fit & comfort). Compatibility with other equipment. Cost. Inspection to detect defects. Proper storage. Replacement of defective equipment.

Exercise 7 Describe the TVVOmain types of personal hearing protection. Answer 7 • •

Earplugs: are small pieces of acoustic absorbing material. Ear defenders (ear muff): are designed to cover the ears externally with large cups held in position by a head band. The cups contain polyurethane foam or liquid.

Exercise 8 Outline the factors to be considered in the correct selection of respiratory protection for use at work. Answer 8 • • • • • •

The nature of the contaminants (dust, vapors, fumes, etc.). Contaminants concentration & toxicity. Compatibility with other equipment. Ergonomic issues. Maintenance requirements. Storage requirements

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NEBOSH National General Certificate • •

Conformance with standards. Cost.

Exercise 9 Identify FOUR different types of hazard that may necessitate the use of special footwear explaining in EACH case how the footwear affords protection. Answer • • • • • • • • •

9 Falling objects: requiring use of steel-toe-caps. Sharp objects: steel-in-soles. Flammable atmosphere: antistatic footwear(spark proof) Molten metal: heat resistant boots and gaiters. Electricity: rubber soles. Wet environments: impermeable Wellington boots. Slippery surface: non-slip soles. Spread of contamination: washable boots. Cold environments: thermally insulated footwear.

Exercise 10 Identify the types of hazard against which gloves could offer protection. Answer 10 • Hot work: use leather glove. • Abrasion protection: use leather or PVC glove. • Handgrip: use cloth glove. • Cut protection: use chain mail glove. • Paint spray: use rubber glove. • Electrical work: use natural rubber-latex glove. • Biological agents: use surgical glove (made of latex).

Exercise 11 Outline the practical limitations of using gloves as a means of protection. Answer 11 • Impairment of dexterity: on wearing gloves, dexterity is impaired which means: o Things that might be dropped. o Delicate adjustments cannot be accomplished. • • • • •

Entanglement in machinery: on using glove on dealing with machinery as a drill, it will constitute an entanglement hazard. Torn or puncture: if the glove is torn or punctured it will expose the skin to the hazard. If the glove material is not properly selected for the hazard it will not offer protection (as for example chemical can penetrate the glove). Allergy: allergic response occurs in some sensitive people and with some kinds of glove as latex. Infection of hand: if good hygienic practices are not followed & the glove become internally contaminated.

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NEBOSH National General Certificate Exercise 12 Outline the general issues relating to the selection and use of PPE that will help to ensure its effectiveness in controlling hazards.

Answer 12 • • • • • • • •

Appropriate for the hazard: as for example respirator with gas cartridge for gases. Complying with standard with CE quality mark. Adjustable (if possible) to be fitted to the user 0 it will be comfortable and will be accepted by the user. Compatible wit other terms (if more than one PPE are used. Not impairing mobility, vision, hearing, etc. of the wearer. Not affecting the ability to do the task (for example wearing gloves affect the wearer's ability to do fine adjustments by hand.) Not creating other risks (as gloves for example may create entanglement risk on working on machines as drills). Of reasonable cost "regarding replacement, maintenance & training on its use."

Factors that should be considered • • • • • •

for PPE use are:

Provision of the required informants, instruction & training to employees. Cleaning, inspection and maintenance requirement. Storage requirements Procedure for replacement of damaged equipment. System for reporting defects or loss. Supervision and monitoring of use.

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NEBOSH National General Certificate Manual handling

Exercise 1 List two types of injury that could be caused by incorrect manual handling of loads.

Answer 1 • • • • • • •

Spinal disc compression Torn ligaments. Joint dislocation. Muscle strains. Hernias. Crushing injury. Fractures, cuts, burns.

Exercise 2 Outline a good handling technique from the ground.

that could be adopted by a person required to lift a load

Answer 2 • • • • • • • •

Foot position: feet to be shoulder width apart with one leg forward: Be close to the load. Allow the heavier part of the load next to you. Lift with legs. "bend knees & keep back straight". Straight back. Firm grip using full hand. Elbows in. Chin in and "raise head while lifting, this will ensure straight back."

Exercise 3 Define the term "manual handling"

Answer 3 -Manual handling: is moving or supporting a load by hand or body force. -Or it is the movement or support of a load by physical effort including: lifting, carrying, pushing, pulling or moving.

Exercise 4 Outline the practical measures activities at work:

designed to reduce the risk of injury from manual handling

Answer 4 • • • • • •

Mechanization of manual handling activities (as use of forklifts, conveyor belt, etc.). Team handling. The adoption of kinetic handling techniques. Smaller, lighter and more stable loads. Redesign task to reduce the need for: stooping, twisting or overreaching. Improving environmental conditions.

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NEBOSH National General Certificate •

Selection and training of personnel

to carry out manual handling activities.

Exercise 5 Outline the factors associated with working environment risks:

that may affect manual handling

Answer 5 • • • • • • •

Space constraints. Floor conditions (slippery, uneven or varying in height). Extremes of temperature. Humidity. Air movements & ventilation. Lighting. The physical layout: it may lead to excessive carrying, lifting or lowering distances.

Exercise 6 Describe the FOUR factors that should be considered when making an assessment handling operations.

of manual

Answer 6 • •

• •

Load: weight, size, stability, height, contents, outer surface, lack of rigidity (smoothness), the ease with which it can be grasped, etc. Task: distance of the load from the trunk, body movements & postures required (as stooping, twisting, overreaching), excessive pushing or pulling, excessive handling distances, etc. Environment: ventilation, lighting, space, floor conditions, (slipping or tripping, uneven etc.), Individual: physical capabilities, health (fitness, pregnancy, etc.)

Exercise 7 Outline the task factors that may affect manual handling risks.

Answer 7 • • • • • • • • • • •

Position of load in relation to body: (handling loads close to the body are less hazardous) . Is the task requiring excessive pushing or pulling of loads. Is the task requiring loads to be lifted from or to be returned to the ground level. Is the task necessitates stooping while handling (restricted headroom as in confined space). Is the task necessitates overreaching (as in lifting loads & putting it in a store above head level). Is the task involves twisting of the body. Is the task imposing excessive handling distances. Is the task imposing repetitive handling. Is the task not providing sufficient rest. Is the task involving sudden movement of loads. Is the task requiring pushing or pulling above or below waist level.

Exercise 8 A store man is required to place boxes of metal components

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by hand onto shelves racking.

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NEBOSH National General Certificate i. ii.

List FOUR types of injury to which the store man may be at risk while carrying out this operation. Outline the factors in relation to the task that may affect the risk of injury.

Answer 8 Examples of injuries are: • Cuts, abrasion. • Crushing injuries. • Strained ligaments and tendons. • Dislocations of joints. • Hernias • Bone fractures. Task factors that may affect the risk of injury:] • • • • • • •

Handling loads at a distance from the body. Excessive carrying, lifting or lowering distances. Excessive pushing or pulling. Pushing or pulling loads above or below waist level. The need to lift from and to return loads to the ground level. Task requiring stooping, twisting or overreaching. Task requiring repetitive handling with no sufficient rest periods.

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NEBOSH National General Certificate Mechanical Handling and Transport Safety

Exercise 1 Outline the hazards and the corresponding for fork lift trucks.

precautions to be taken when changing batteries

Answer 1 The • • • •

Hazards accompanying changing batteries for fork lift truck: Fire/Explosion hazard. Chemical corrosivity: due to battery chemicals. Electrical hazards-short circuit. Manual handling hazards: due to lifting of batteries.

The precautions to be taken when changing batteries for a fork lift truck. • Exclusion of ignition sources. • Proper ventilation. • The use of suitable PPE. • Emergency washing facilities. • Team handling of batteries or use of mechanical aids. • Electrical safety precautions as: Insulating covers, non-conducting tools & proper con nections.

Exercise 2 Outline FOUR hazards and the corresponding materials.

precautions in the use of conveyor systems for

Answer 2 Hazards Drawing in (nips) Impact from fallinQ objects Entanglement

Cuts, abrasion & crushing

Precautions -Nip guards -Fixed Quards -EdQe Quards -Ban on using jewellery, ties, loose cloths, etc. -Covering hair with helmet, cap, scarves, hair net, etc. -Guarding (fixed guards). -Emergency stop buttons. -Trip devices -Jump-out rollers (to push the victim out of danQer.

Types of fork lift trucks: -LPG "gas" -Diesel -Electric

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NEBOSH National General Certificate Exercise 3 Outline the precautions to be taken to prevent accident to employees working at ground level in a workshop where heavy loads are lifted and transported by means of an overhead gantry crane.

Answer 3 • • • • • • • •

Key personnel (operator, slinger & signaler) are to be competent & properly trained. Maintenance and statutory requirements of the crane and lifting tackle. Audible & visual warning (that a dangerous lifting operation is taking place). Ensuring security of the load. Ensure load not exceeding SWL (safe working load). Ensure load is lifted to the correct height & is moved at an appropriate speed. Ensuring that all those working in the area have been properly trained & adequately supervised. Stand-by emergency services.

Exercise 4 Outline EIGHT types of hazard associated

with the operation of forklift trucks.

Answer 4 •

Overturning:

• •

Collision Connect with

• • • • •

due to overloading,

unsuitable

ground, sudden brake, etc.

hot surface. battery acid Manual handling batteries LPG cylinder Explosive atmosphere from leaking cylinders. Exhaust fume emissions. Loss of loads. Electrical short circuit ( in electrical forklift).

Exercise 5 List the ways in which a forklift truck may become unstable whilst in operation.

Answer 5 • • • • • • • •

Insecure, excessive or uneven loading. Incorrect tilt and / or elevation of forks when traveling. Uneven or unconsolidated ground. Incorrect procedures to deal with slopes. Cornering at excessive speeds. Sudden breaking. Poor condition of tyres. Mechanical failure.

Exercise 6 List the items included in the checklist beginning of a work shift.

for the routine inspection

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of a forklift truck at the

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NEBOSH National General Certificate

Answer 6 • • • • • •

General condition of brakes & steering. Warning devices (horns and flashing beacons). Condition of tyres. Lifting mechanism (mast, chains, & fork). Correct adjustments of seat & mirrors. Oil leak.

Exercise 7 Outline the main precautions substances by road.

to be taken to ensure the safe transport of hazardous

Answer 7 • • • • • •

Planning the route of transport. Suitable containers for hazardous substances (containers made of material not reacting with chemical, securely closed, etc.) Segregation of incompatible materials. Emergency information (HAZCHEM signs and TREM cards). Emergency provisions (for first aid facilities and fire extinguishers). Appropriate driver training (including fire fighting).

Exercise 8 Outline a procedure for the safe lifting of a load by the use of a crane, having ensured that the crane has been correctly selected and positioned for the job.

Answer 8 The suitability of lifting tackle: • Of a good construction, sound material, adequate strength and free from defects. • SWL to be displayed and not exceeded • To be examined by a competent person every 6 months. The competence

of the persons involved: Driver, Slinger, Signaller.

The load: To ensure that: • The load is secure. • The load is lifted vertically. • The load is balanced and controlled necessary.

during the lift by the attachment of tag lines where

*Proper Communication: between driver and banks men. *Rate of performing the operation: To perform each part of the operation as lifting, swinging, moving & lowering at a rate that maintains proper control. *Keeping the area clear of other persons.

Exercise 9 Describe the procedure that should be taken when slings are used to lift loads.

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NEBOSH National General Certificate Answer 9 The suitability of lifting tackle: • Of good condition, sound material, adequate strength and free from defects. • SWL to be displayed and not exceeded. • To be examined by a competent person every 6 months. Load handling & control: • Slings to be attached to the lifting appliance correctly. • Use the slinging method that ensures security of the load (if using multiple slings "2 or 3 legged etc." the load should be evenly distributed so that no leg is overloaded). • The load is to be lifted vertically and to be balanced and controlled during lift. *Proper communication: between driver and banks men using correct signals and the use of radio. Never allow any person other than banks men give signals. *Keep the area clear of other persons.

Exercise 10 Outline the measures that can be taken to reduce the risk of accidents when pedestrians are required to work in vehicle maneuvering areas. Answer 10 • • • • • • • •

Keep people and vehicle apart: by providing, where possible, specific routes for pedestrian. Crossing points over loads. Suitable barriers at road entrances. Separate access for pedestrians. Road sings and barriers. Speed limits for vehicles. ( inform of hampers, signs, etc.) Reflective clothes for pedestrians. Adequate lights for the area and the use of warning flash lights.

Exercise 11 Describe the main hazards associated with electrically operated forklift trucks. Answer 11 Electrical hazards: • Explosion due to contact of live cables with the metal of the truck frame and the shorting of battery terminals by metal tools or lifting tackle. • Battery spark leading to ignition of hydrogen "Generated during charging" leading to a dangerous explosion. Non - electrical hazards • Overloading • Over turning • Collision. • Loss of Load. • Overhead obstruction. • Truck failures. Exercise 12 The Key Consultancy

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NEBOSH National General Certificate Produce a checklist that could be used in the design of safe system of work dealing with pedestrian operated vehicles.

Answer 12 • • • • • • • • • •

Vehicles maintenance and certification. Walkways for pedestrians. Adequate lighting. Warning signs. Speed limit. Required reflective clothes. Separate access and crossing points for pedestrians. Road barriers Road signs. Flash lights.

Exercise 13 Outline the precautions

that should be taken when using mobile cranes.

Answer 13 • • • • • • • • •

The crane must be suitable (test certificate, reach, lifting capacity etc.) The crane is to be used on stable and level base. Outriggers should be used effectively and correctly "to be fully extended and locked on all slides" Avoid obstruction/overhead lines. The height limit structure should be erected, decked with warning flags. Suitable lifting tackle. Correct slinging techniques. Ensuring competence of personnel (driver, slinger, and signaller). Ensuring good visibility & communication.

Exercise 14 What are the main conditions required for the safe storage of ropes.

Answer 14 • • •

Store need to be dry, well ventilated and free from corrosive atmosphere. Natural manmade fiber ropes should be stored away from direct sunlight. All stores should have: -An area for simple maintenance, -A security system. -Recognized office areas.

Exercise 15 Enlist the THREE types of jacks:

Answer 15 •

Screw jack

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NEBOSH National General Certificate • •

Hydraulic jack Ratchet jack

Exercise 16 What general precautions to be observed when jacks are used. Answer 16 • Test and certificate. • SWL marking. • Sound level footing. • Load balance. • Packing must be placed under the load. • One person to control the load when two jacks are used. • Jack head & toe to be free from grease. Exercise 17 Outline the factors to consider when assessing the risks to a long distance delivery driver. Answer 17 • • • • • • • • • • •

Route demands: complexity, road conditions, etc. Duration of the journey. Security issues: e.g.: potential for violence cab. Means of communication available to the driver to be used in cases of emergencies. Driver capabilities (physical & psychological) to cope with the demands of the job. Level of training provided to the driver. Vehicle maintenance. Design and layout of the vehicle cab. Nature of the load (hazardous material, heavy, etc.) Means of handling materials available. Emergency procedures in place.

Exercise 18 Outline EIGHT rules to follow when a forklift truck is left unattended in the workplace. Answer 18 • • • • • • • • •

To be left on a finn level ground in a designated area with the mast titled slightly forward the forks resting on the floor. The truck is to be switched off. The key to be removed and to be given to a responsible person (to prevent unauthorized use of the truck). The truck should not be left until the brake has been applied. To be parked away from the vehicles. To be parked away from adverse environmental conditions as rains. To be parked in a positions that does not obstruct emergency exits, walkways, etc. Keeping regular maintenance of the truck even if not attended. If the truck is to be left unattended for a long period, it may be useful to: -Isolate electricity if the truck is electrically operated. -Remove the battery (if it is battery operated). -Remove LPG cylinder (if is gas operated).

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NEBOSH National General Certificate

Exercise 19 Outline the means by which the risk of accidents can be reduced.

from reversing vehicles within a workplace

Answer 19 • • • • • • • • • • • • • •

Elimination of the risk (redesign task to eliminate the need for vehicles to reverse). The availability of banks men to lead the vehicle. Good communication between vehicle driver and banks men. Marking of the route of the vehicle. Proper lighting of the area. Speed limits within the workplace. Worker to provide with visibility clothes to be useful especially at night. Proper selection and training of vehicle drivers. Availability of mirrors in the "Rear view concave mirror". Availability of mirrors in the work place especially on the turns and corners, Audible and visual alarms (flashing beacons). Proper supervision of driver acts. Disciplinary action to be taken for any violations of unsafe acts by the drivers. Control measures so that to prevent the use of vehicles by unauthorized persons.

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NEBOSH National General Certificate Working Equipment Exercise 1 Identify: 1) TWO mechanical hazards associated with moving parts of machinery. 2) TWO non-mechanical hazards to which the machinery operator may be exposed. Answer 1 Mechanical Hazards Associated with moving parts of Machinery. • • • • • • •

Impact. Crushing. Entanglement. Shearing. Cutting or Stabbing. Abrasion. Puncture (as by the needle in sewing machine).

Non - Mechanical hazards include: • • • • • • • •

Noise Vibration Electricity Hazardous substances as Gases Radiation Heat Hazards Ergonomic Hazards Hazards related to the operator

Details about Mechanical Hazards of Equipment: •

• • • •

Entrapment: where parts of the body (as hands or fingers) are caught or trapped in parts of moving machines. It is either Nips When Trapping occurs between 2 moving parts) or Shear (where Trapping occurs between one moving against fixed part.) Entanglement: where hair, clothes, jewellery, etc. are caught in p[arts of a revolving machine. Impact: where the body is impacted by moving parts or processed items. Ejection: where the parts of the machine or materials being used fly out and hit the body. Contact: where the body touches: o Sharp cutting edges. o Abrasive surface. o Hot items o Live electrical items.

Exercise 2 Provide Sketches to the show clearly the nature of the following. Answer 2

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NEBOSH National General Certificate Mechanical Hazards from the moving parts of Machinery; & Shear. Exercise

Crushing, Drawing in

3

Outline FOUR requirements "PUWER,1998" Answer

Entanglement,

of the Provision and Use of Work Equipment

Regulation, 1998.

3

• • • ..,./ •

Ensure suitability of the equipment for the purpose. Maintenance to keep in efficient state, working order and good repair. Inspection: on installation or where it could deteriorate and lead to danger. Risk assessment. Training: ensure users, supervisors & managers receive training.

•

Conformity - Must Comply with: Essential safety requirement (ESR). EU directives. British / European standards.

•

Dangerous

parts must take effective measures to: Prevent access to it. Stop the movement of the dangerous zone.

part before entry to the danger

~

Control system & Emergency Stop Controls Isolation from sources of energy. ~ .. Stability in place. Lighting in machine area. -. Safety of maintenance operations. ~ Warning System. ~

'-v

Exercise

4

Identify FOUR mechanical injury may occur.

Answer • • • •

hazards presented by pedestal drills and

outline in each how

4 Entanglement: where hair, clothes, gloves, etc become caught in the bit or chuck. Ejection: of a work piece or broken bit. Stabbing or puncture: from the end of the drill bit. Impact: from an unsecured (revolving) work piece.

Exercise

5

Outline FOUR hazards associated Answer

with the use of photocopy

machine.

5 • • • •

Sharp edges: during cleaning or clearing jams. Electricity hazards: due to faulty wiring. Hot surfaces: during copying. Exposure to chemicals (as cleaning solvents & dust during machine cleaning).

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NEBOSH National General Certificate • • • •

Manual handling hazards: due to lifting paper & items to be copied. Ozone exposure Ergonomic hazards: due to improper design of the workstation Ultraviolet light hazard.

Exercise 6 Explain the precautions that should be taken to ensure the safe use of photocopying machine. Answer 6 •

Precautions to ensure safe use of Photocopying Machine are proper workstation design (space, lighting, layout, etc.), interlocked guards, adequate ventilation, warning signs (e.g.; relating to hot surfaces), Machine maintenance, protective clothes (e.g.; gloves when replacing toner) appropriate Training regarding safe use, and electrical safety precautions with replacement of faulty wiring.

Exercise 7 Outline the possible risk to health and safety faced by the operator of a pneumatic drill on highway. Answer 7 •

Noise hazards: the likelihood & consequences of noise exposure-Noise induced hearing loss. Vibration hazards: likelihood & consequences of vibration - Vibration white finger. The presence of underground services: with the risk of electrocution, etc The proximity to vehicles: with the risk of collision. Manual handling of equipment: with the risk of occurrence of back problems, etc. Dust: causing irritation of eye, respiratory tract, etc. Projectiles: with the risk of occurrence of eye injury. Heat hazard: with the risk of occurrence of heat stroke. Bites by animals: is rare but may occur. Adverse environmental conditions as rains, storms, etc.

• • • • • • • • •

Exercise 8 Outline the basic safety rules that could be given to a worker using hand tools: Answer 8 • • • • •

To To To To To

wear the suitable protective clothes (goggles, gloves, etc) report any defect in the tool before using it. be sure that work surface is clean (before using the tool.) use the tool by the designed safe way . clean the tool after use and to keep it in its designed location.

Exercise 9 In relation to machine safety, outline the principle of the following types of machines guards: - a fixed guard -an interlocked guard Answer 9 A fixed Guard: • Is a physical barrier that prevents access to danger area. The Key Consultancy Ltd 2005: All Rights reserved

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NEBOSH National General Certificate • • •

Is not connected to machine controls. With no moving parts. Is so fixed that it requires a special tool (e.g. spanner) to remove it. An interlocked Guard: Is linked with machine controls such that the guard cannot be opened if the machine is in a dangerous condition or opening the guard cause the machine to become safe.

•

Exercise 10 List two advantages and two disadvantages

of a fixed machine guard.

Answer 10 Advantage of a fixed guard: • •

The simplicity (easy to inspect and maintain). Is more reliable (as it contains no moving parts).

Disadvantage • • •

of a fixed guard:

If the guard is removed, no protection is afforded. The guard is fixed and requires a special tool to remove meaning that the access, when required, will be difficult. As a physical barrier (especially if it is solid rather than meshed) may hamper inspection of the machine or the work being performed.

Exercise 11 With the aid of sketch describe a situation where a fixed would be used.

Exercise 12 Enlist the circumstance

in which the use of a fixed guard is impractical.

Answer 12 • • •

Where there is a need for frequent access to danger area. Where there is a need for frequent maintenance operations removal of the guard.) Where there is a need for clear vision of the work piece.

(thus require frequent

Exercise 13 List TWO advantages

and TWO disadvantages

of a interlocked

machine guard.

Answer 13 Advantages of an interlocked machine guards: • It allows safe access (as for maintenance). • Is convenient to use. It prevents access only when danger is present. Disadvantages of an interlocked • Complexity. • Difficult to test and maintain.

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NEBOSH National General Certificate Exercise 14 With the aid of a sketch describe the main features of an interlocked guard. Exercise 15 List the hierarchy of Control measures that may be used to reduce the risk of injury from dangerous parts of machinery. Answer 15 • • •

• •

Redesign task to eliminate the hazard (by avoiding the need for hazardous machines). Substitution of hazardous machines by less hazardous ones. Engineering controls (Guards): If access to danger area is not required: -Fixed guard. -Distance guard. If access to danger area is required: -Interlocked or Control guard. -Automatic guard. -Trip Device -Adjustable guard. -Two-handed control guard. Provision of information, instruction and training. Use of suitable PPE.

Exercise 16 Outline the precautions that should be taken for the routine maintenance of machinery. Answer 16 • • • • • • • • •

Segregation of the area (by barriers, warning signs, etc.) to prevent unauthorized access. Ensure isolation of power sources. Permit to work including dissipation of stored energy as pressure release, cooling of hot surfaces, etc. before work commences. Safe means of access using ladders, scaffolding, etc. Installation of additional lighting and ventilation where needed. Ensuring competence of the staff and proper supervision for the process. Provision of correct tools. The use of required PPE (as gloves, goggles, respirators, harness, etc.). Stand-by personnel and first aid and emergency facilities.

Exercise 17 Outline the principle of operation of Trip Devices: Answer 17 • • • •

Is a guard which stops or reverse the machine before the operator reaches the hazard area. It relies upon sensitive trip mechanisms. Its maintenance is top priority. Example is the photoelectric guard used for hydraulic presses. It operates by creating a light - curtain across the hazard area. If any of the beams is broken, the unit will stop.

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NEBOSH National General Certificate •

Another example is Trip mats which are positioned around a machine. It contains switches which stop the machine when they are Trodden on.

Exercise 18 A local authority employee uses a Petrol driven strimmer to maintain roadside grass. 1) Outline the hazards of this operation. 2) Identify five types of PPE required to be used. 3) Outline the control measures required to avoid the risk of this operation. Answer 18: Hazards are: • Equipment Hazards: as cutting, ejection, noise, vibration, etc. • Chemical hazards: due to exhaust fumes. Carbon monoxide hazards is an example. • Flying stones and sticks: leading to eye injury, body cuts, bruises, etc. • Feet and/or legs injury: due to ground stones, projections, grass, etc. • Electric shock: due to short circuit in wet conditions, cutting cables, etc. • Biological hazards: due to contaminated ground. • Heat hazards: due to working under the sun. • Tripping hazards: due to trailing cables, piles of trimmed grass, etc. • Fire & explosions hazard: due to smoking for example in the area. • Collision by vehicles. • Bites by animals, snakes, etc. The PPEs required: • Eye goggles: to protect eyes from flying stones/sticks. • Face shield: to protect face. • Safety shoes & gaiters: to protect feet & legs. • Helmet: to protect from Sun & also from any flying objects. • Ear plugs and/or ear muffs: to protect from noise. • Suitable overall: to protect the body (visibility belt or clothes are required if working at night). • Respirators: to protect from fumes. The control measures required: • Safety checks for the area before starting work. To ensure: o No wet conditions that may cause short circuit. o No animals, snakes, etc. o The height and area of grass. o The width of the road and the expected impact of the operation on fluency of traffic. • Barriers around the area and warning signs. • Proper selection and training of workers for the job. • Proper selection and maintenance of equipment. • Electrical safety precautions as: use of circuit breakers, use of water proof cables, etc. • Workers to use the required PPE. • Immediate removal of trimmed parts. • Availability of first aid & emergency measures.

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NEBOSH National General Certificate Exercise 19 A cleaner is required to polish floors using a rotary floor polisher. 1) Identify the hazards that might be associates with this operation. 2) Outline suitable measures that might be used to minimize the risk. Answer 19 The hazards include: • Entanglement. • Noise and vibration. • Electric shock. • Chemical hazards due to chemicals used for cleaning. • Slips, trips, and falls. • Manual handling hazards: as back injuries. The suitable control measures: • Signs referring to the hazard • Adequate guarding of rotating parts of equipment. • Electrical safety precautions including o The use of residual current device. o Check condition of cable & plug before use. o Disconnect from power source when changing brushes or carrying out any adjustments. o Avoid contact with water. • The cable should be properly recessed so that not forming tripping hazard. • The cable should not be stretched or over-extended. • Keep lids and caps on chemicals. • Use the appropriate PPE (anti slip shoes, goggles, masks, overalls, etc.) Exercise 20 Outline risk to workers using solvents on cleaning of equipment. Answer 20

•

•

The risks include: Health risk: including: o Contact of solvents with the skin leading to dermatitis. o Contact of solvents with the eye causing eye inflammation. o Inhalation of solvent fumes leading to: • Dizziness Effects on the Central nervous system. • Asthma. Safety risk: including: o Risk of occurrence of fire. o Risk of occurrence of explosion. o Risk of occurrence of mechanical hazards as cuts, bruises & other types of injuries.

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NEBOSH National General Certificate Maintenance

Exercise 1 Enlist EIGHT examples of plant & equipment that require to be maintained by law. Answer 1 • • • • • • • •

Machine guards. Lifting appliances and tackle. Lifting equipment. Steam boilers & pressure systems. Breathing apparatus. Fire extinguishers. Exhaust ventilation plant (LEV). Scaffolding.

Exercise 2 Outline the requirements for a safe system of maintenance. Answer 2 • • • • • • • •

Design: choice & installation of appropriate plant, equipment, etc. Management: maintenance must be managed by experiences personnel and proper supervision. Information: maintenance section must have access to some kind of database covering tasks as: plant and process hazards, safe procedures, etc. Training: is requiring for all maintenance workers. Planning: plans for safe maintenance should be available. Equipment must be put into operation and to be observed to make sure it is working properly. Monitoring: the working environment is required to be monitored to protect staff during maintenance. Rescue & emergency procedure and staff should be available to deal with any event.

Exercise 3 What sort of precautions maintenance workers should take when dealing with a damaged asbestos product? Answer 3: • • • •

Avoid breathing in the dust (wearing respirator with dust cartridge is helpful). Follow the working methods described in the approved code of practice or required by Asbestos Regulations. Well-sealed, undamaged asbestos is often best left alone. Make sure all asbestos is clearly identified, sealed and protected against further damage.

Exercise 4 Outline the precautions that should be taken for the routine maintenance of machinery.

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NEBOSH National General Certificate Answer 4 • • • • • • • • •

Segregation of the area (by barrier, warning signs, etc.) to prevent unauthorized access. Ensure isolation of power sources. Permit to work including dissipation of stored energy as pressure release, cooling of hot surfaces, etc. before work commences. Safe means of access using ladders, scaffolding, etc. Installation of additional lighting and ventilation where needed. Ensuring competence of the staff and proper supervision for the process. Provision of correct tools. The use of the required PPE (as gloves, goggles, respirators, harness, etc.) Stand-by personnel and first aid and emergency facilities.

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NEBOSH National General Certificate "ELECTRICAL

SAFETY"

Exercise 1 Describe the functions and limitations of a fuse as an electrical protection device. Answer 1 The function of a fuse: *The fuse is a weak link in the live supply that melts when heated by excess current flowing under fault conditions, thus protecting the equipment and its wiring. The limitations of a fuse: - Its action is too slow to prevent electric shock. - It can be easily replaced inappropriately with a fuse of higher rating. Exercise 2 Identify TWO advantages that a residual current device (RCD) has over a fuse. Answer 2 Advantages of residual current device (RCD) over a fuse: • Rapid and sensitive electrical response. • Ease and safety of testing. • It is not easily defeated.

Exercise 3 Describe the principles of operation of the following types of electrical protection. a) b)

Earthing. Reduced voltage.

Answer 3 Earthing: -It is a means of connecting electrical equipment and conductive items to earth by a cable or pipe work such that the route to earth provides the path of least resistance to a current flowing under faulty conditions. Reduced Voltage: -Use of the lowest practicable voltage should be practiced in every circuit (the use of 110 V transformer is recommended). Exercise 4 Outline: -The effects on the human body of a severe electric shock. -The emergency action to be taken if a person suffers a severe electric shock. Answer 4

•

The effects on the human body of a severe electric shock: Primary effects: due to electric shock on the human body physiology leading to: *painful shock

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NEBOSH National General Certificate *muscle cramps & convulsions. *electric bums in skin & internal organs. *cardiac & respiratory arrest. •

Secondary effects: due to fall from a height including for example: Fracture, bleeding, etc.

•

The emergency

action to be taken if a person suffers a severe electric shock:

*Isolation of the electric supply "if possible". *Removal of the casualty from electric contact (using isolating material). *Summoning help *Cardio pulmonary resuscitation (CPR). *Treatment of burns and other injuries. *Remaining with the casualty until medical help arrives. Exercise

5

Outline the practical measures electrical appliances. Answer

to reduce the risk of electric shock when using portable

5

• • • • • • • • •

Proper selection of the equipment "to be suitable for the purpose" Inspection and testing of the equipment. The use of reduced voltage or battery-powered equipment. Double insulation. Earthing. Use of protective devices (as RCDs & fuses) Sound connections. Proper storage of equipment. Training to be given for equipment operators.

Exercise

6

List of items that should be on an inspection checklist designed portable electric appliances. Answer • • • • • • • •

to ensure the safety of

6 Equipment is appropriate for the task. Equipment is appropriate for the environment. Equipment is regularly tested. Equipment, cables, connectors, switch and plugs are free from damage. Correct wiring. Sound connections. Protective devices (as fuses) are in place and are of correct rating. Accessible and appropriate means of isolation.

Exercise

7

Outline the precautions to protect against electrical contact when: -Excavating near underground cables. -Working in the vicinity of overhead power lines. Answer

7

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Excavating near underground cables: • Isolation of the electrical supply. • The identification of cable routes from plans and by the use of cable detector. • Marking of cable routes on sites. • Digging with hand tools rather than by mechanical excavator.

•

Working in the vicinity of overhead power lines: • Isolation of the electrical supply. • Erection of barriers to define clearance distances. • Clear marking of danger zones (e.g.: with signs). • Ensuring safe access routes under lines (e.g.: with tunnels). • Restriction of metal items as ladders or scaffolds tubes near the lines.

Exercise 8 In relation to electrical safety, explain the meaning of the following terms: -Isolation. -Over current protection. Answer 8 *Isolation: refers to shutting off the electrical supply to an item of equipment or part of an electrical system by a safe means in order, for instance, to carry out maintenance work. *Over current protection: is a method of preventing the flow of excess current by cutting the supply under fault conditions by means of a fuse or circuit breaker (as a miniature circuit breaker). Exercise 9 a) List the main hazards associated with maintenance on a electrical equipment. b) Outline control measures to minimize the risk of electric shock during such work. Answer 9 a) The main hazards are: • Electric hazards: due to live work / not isolated / re energized, lack of protective equipment, etc. • Ergonomic hazards: due to restricted working space, access or lighting. b) The required control measures are: • Provision of adequate working space, access and lighting. • Adoption of good working practices. • Provision of training & supervision. • Electrical precautions including: o Limited voltage supply. o Use of residual current device o Proper insulation or enclosure of equipment and wires. Exercise 10 A decorator uses a hand-held electric sander for the preparation of wood prior to painting. 1) Outline the checks that should be made to ensure the electrical safety of the sander. 2) Other than electricity, identify FOUR hazards associated with the use of the sander.

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NEBOSH National General Certificate Answer 10 1) The checks that should be made are: Checks to ensure that the equipment meets the recognized standards: o Fuses are of correct rating. o Electrical connections are sound. o Eartnig continuity is achieved. o Voltage is low reduced voltage. o Appliance is double insulated Check by the user immediately before use: o Visual inspection of appliance general condition. o Integrity of plug and cable. o Integrity of any extension leads. o Integrity of the sockets from which supply is taken. o Further checks depending on type of equipment as to ensure that it is protected by a residual current device. 2) Examples of the other hazard: o Dust hazards. o Noise hazards. o Vibration hazards. o Tripping due to trailing cables. o Ergonomic hazard (related either to equipment design or to the way in which the work is carried out). Exercise 11 State the items that should be included on checklist for the routine inspections of portable electrical appliances: Answer 11 • • • • • • •

Casing of appliance: in good condition. Cable secure and not damaged. Plug: not damaged. On/Off button: accessible, not damaged and working efficiently. Fuses: fitted and correctly rated. Equipment: operated at reduced voltage where appropriate and/ or fitted with residual current device. Equipment to be tagged showing date next test due.

Exercise 12 Outline the dangers associated with electricity: Answer 12 • • •

Electric shock: is dangerous as it can cause stopping of heart and respiratory rhythm and necessitate rapid interference. Tissue burns: electric burns are deeper than other burn types and take longer time to heal. Fire and explosion: electrical spark is one of the ignition sources that may initiate a fire. Unsafe electrical equipment may give sparks that can catch fire if near to a paint can for example.

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Secondary effects: such as falling from a height as a result of electric shock. This will lead to fractures, bleeding, organs damage & death.

Exercise 13 Outline measure that should be taken to minimize the risk of fire from electrical

equipment.

Answer 13 • • • • • • • •

Proper selection of the electrical equipment: with CE quality mark, suitable for the task, etc. Inspection of the equipment by the user prior use. Establishing correct fuse rating. Ensuring circuits and sockets are not over loaded. Disconnecting the equipment to electricity when it is not in use. Ensuring the electrical motor vent are uncovered (to prevent its overheating). Regular inspection, testing and maintenance by competent persons. Uncoil cables (to protect cables from mechanical damage and to prevent build-up of heat.

Exercise 14 Describe FOUR features of an environment electric equipment.

that could increase the risk from using portable

Answer 14 -Wet environment: electric shock can occur due to the use of electric equipment in a wet environment (water is electrically conductive) -Flammable atmosphere; which can predispose to fire if a spark comes from the equipment. -Windy environment: can predispose to falling hazard especially on using equipment in a work at height using improper secured ladder. -Poor lighting: can predispose to accidents (as tripping on trailing cables, etc.) -Poor ventilation: affect the efficiency of the operator and increase the likelihood of human error. -Noise: same effect as poor ventilation in addition to interference with good communication. -Floor condition: slippery or uneven floor can lead to slipping or tripping while using the equipment.

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NEBOSH National General Certificate FIRE

Exercise 1 Explain why water not to be used as an extinguishing agent for use on fire involving: -Petroleum Spirit -Electrical Equipment Answer 1 -Petroleum Spirit: Because petroleum spirit will float on water and will therefore continue to burn, or vaporize to form an explosive cloud, water may also spread the fire over a larger area. -Electrical Equipment: The electrical conductivity of water is well known and thus water extinguisher can lead to the risk of electric shock and possible explosion. Exercise 2 Outline the main factor to be considered when sitting portable fire fighting equipment. Answer 2 • • • • • •

Accessibility to users. Proximity to fire exits and escapes routes. Visibility and Signage. Location off the ground with adequate support. Suitable type in relation to the hazard present. Protection against damage and weather.

Exercise 3 Explain with an example, the meaning of a Class 0 fire. Answer 3 The meaning of class - 0 fire: Is the type of fire involving metals as Sodium, Magnesium, Potassium, Titanium, Calcium, Zirconium, Lithium and Zinc.

Exercise 4 List two extinguishing agents suitable for use on Class 0 fire. Answer 4 Extinguishing agents suitable for use in Class - 0 fire: -Powdered Graphite. -Powdered Limestone. -Sand.

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NEBOSH National General Certificate Exercise 5 List FOUR sources of ignition that should be considered when storing and using flammable solvents.

Answer 5 Sources of ignition that should be considered when storing and using flammable solvents: -Nacked flame. -Hot surfaces. -Friction Sparks. -Electrical sparks.

Exercise 6 Identify TWO extinguishing agents that can be used on fires that involve flammable solvents and explain their mode of actions. Extinguishing agents that can be used on fires that involve flammable solvents:

Answer 6 Extinguishing Agent Dry Powder

Mode of Action -Exclusion of Oxygen (smothering)

Foam

-Smothering -Cooling

Sand Carbon dioxide

-Smothering -Smothering

Exercise 7 Explain the methods by which a fire can spread. Answer 7 1) Conduction: Materials as metals are good heat conductors while glass and wood are insulators. 2) Convection: When a gas is heated it expands and become less dense and thus it moves up. This explains the spread of fire to the upper storey of a building due to hot gases rising up lift shafts and stairwells. 3) Radiation: Heat is transferred as invisible rays through the air. Example: Clothes hung near an electric heater for drying could ignite and flame can jump across a street to the building nearby. 4) Direct burning: of a combustible material in naked flame.

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NEBOSH National General Certificate Exercise 8 Outline the safety precautions that should be taken when storing and using flammable solvents.

Answer 8 The safety precautions that should be taken when using and storing flammable solvents: -The quantities of flammable solvents stored. (To be kept to the minimal). -Flammable solvents container type. (To be made a material not reacting with the chemical & to be securely closed). -Precautions for storerooms and cabinets. (To be in an external separate area, of proper layout, with good lighting, ventilation, suitable temperature, good housekeeping & proper stacking of chemicals). -Exclusion of ignition sources. -Prevention of flammable vapour build-up. -Signs and marking. -Provision of the fire fighting equipment. -Provision of emergency arrangements.

Exercise 9 List EIGHT rules that may reduce the risk of fire starting in the work place.

Answer 9 • • • • • • • • • • •

Good housekeeping measures. Refuse and waste disposal control. Safe storage of flammable substances. No-smoking policies. Hot work permits. Proper design and regular maintenance of machines to avoid hot surfaces. Controls on Contractors. Safe electrical systems. The segregation of areas with oxygen-enriched atmospheres as in hospitals. Do not cover ventilation outlets on equipment e.g.: Computers, Heaters, etc. Security issues / arson prevention.

Exercise 10 Outline TWO advantages extinguishing fires.

and TWO disadvantage

of using hose reels as a mean of

Answer 10 Advantage of using hose reels: • It provides a continuous supply of water and at a greater force than that provided by extinguisher. • Users do not need to place themselves in close proximity to the fire.

Disadvantages of using hose reels: • The effort required to position the hose.

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The possibility of the hose comprising fire and smoke barriers by passing through doorways. The hose becoming a tripping hazard and hindering evacuation. Water is not suitable extinguishing medium for all classes of fire.

Exercise 11 Outline the factors to be considered when siting hose reels in the work place. • • • • •

Accessibility to user. Area to be covered. Prevention of obstruction and facilitation of escape. (Reel should be situated adjacent to an exit such that the user is placed between the fire and escape route). Hose reels should be recessed in order to prevent obstruction of an escape route. It should be placed in a position where it would be less prone to misuse and vandalism.

Exercise 12 Identify FOUR different types of ignition sources that may cause a fire and for each type identified outline the precautions that could be taken to prevent a fire starting.

Ignition Source

Precautions

Naked flame Electrical sparks

Care in using instrument with naked flame & to exclude any flammable substance nearby. Electrical protective measures (as Isolation, Earthing, Fuses, Maintenance & Safe system of work, Spark proof equipment.

Heat build-up

Machine lubrication. Avoid coverinQ ventilation holes.

Hot work

Hot work pennits Waminq siqns.

Cigarettes

Prohibiting smoking.

Exercise 13 Outline the inspection and maintenance requirements for fire extinguishers in the workplace •

Inspection of the fire extinguishers: • Usually takes the form of routine (e.g.: monthly) visual checks. The aim is to ensure that: • Extinguishers are place. • Extinguishers have not been discharged. • Extinguishers bear no obvious damage.

o

Maintenance of fire extinguishers: • Is more extensive than inspection. It usually involves annual tests by a competent person.

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Exercise

The aim is to ensure: • The integrity of the extinguisher. • Replacement of equipment found to be faulty.

14

Fire has FOUR classes A, B, C, and O. Identify: -The type of Fuel and -TWO extinguishing agents that could be used for each class. Fire A

B C

D

Exercise

T pe of Fuel Solid (as wood, glass, clothes, papers, etc.) Liquids (as petroleum & aints Gases (as Acetylene, Hydrogen Sulphide, Natural Gas Metals (as Sodium, Magnesium, Aluminum)

Extin uishin '*Water '*D Powder '*Foam '*0 Powder '*Foam '*Dry Powder '*Powder Graphite '*Powdered Limestone '*Sand

15

Explain how to control spread of fire:

Answer 15 •

Proper design of the work place will effectively control fire spread. Design items include: o No access ramps. o No floor openings. o Non-combustible walls & coverings. o Fire doors to prevent flame & smoke spreading. o Casing of metals by insulating materials to avoid spread of fire by conduction. o Partitions between buildings to prevent fire spread by radiation o Automatic Sprinkler System. o Use of extinguishers (water, foam, halon, dry powder or CO2 types). The extinguisher should be of sufficient number, of a type suitable for the class of fire expected, properly sited and regularly inspected & maintained. o Training of workers about firefighting. (Firefighting Training is a necessity for all workers in the workplace and not only for those who are working with the fire "Firemen"), and regular fire fighting drills.

Exercise

16

Explain how to assist the escape of persons in the event of fire.

Answer 16 •

•

Sufficient escape routes (wide, properly lit, ventilated, with no slipping or tripping hazards, with no slipping or tripping hazards, with no-obstructions, not too lengthy, ("Keep travel distance to a minimum"). Sufficient fire exits (open to the outside, tire resistant exit door, etc.).

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NEBOSH National General Certificate • • • •

Separate escape routes & tire exits for disabled. An effective alarm system. Proper insulation and stability of building Regular tire evacuation drills.

Exercise 17 With the reference to the fire triangle, outline Two methods of extinguishing fires. Starving Cooling Fue'/ Fire Triangle

Oxygen ~

Answer 17

Smothering

-Starving: is removal of the fuel from the neighborhood of the fire. Dividing the fire into small fire can be considered also as a starving method. -Smothering: is exclusion of oxygen from the fire environment. Fire needs oxygen to continue same as human needs oxygen to breath. Dry powder, CO2 and sand are extinguishing agents acting by smothering. -Cooling: is removal of the heat component: Water extinguishers act by this way. Exercise 18 State the ways in which person could be harmed by a fire in a work premises.

Answer 18 •

• • • • • •

Burns: due to fire flame. The consequences of burn will depend on: o Site of the burn. o Surface area of the burn. o Degree of the burn (1st degree, 2nd degree or 3rd degree burn). Scalds: are tissue burns due to hot liquids as oils, fats, etc. Electric shock: due to electrical fires (as that involving equipment as TV.). Electric shock can occur also if using water extinguisher for extinguishing electrical fires. Asphyxia: due to inhalation of smoke which replaces oxygen in the atmosphere. Trauma & damage to body organs: due to explosion. Psychological effects. Secondary effect as fracture, bleeding, etc. (after falling from a height for example.

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0xyge~

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NEBOSH National General Certificate CHEMICAL

HAZARD

Exercise 1 State the effects on the body of the following types of hazardous EXAMPLE of each: -I rritant. -Corrosion. -Toxic -Carcinogen

substances giving a relevant

Answer 1 •

Irritant: is a substance that causes an inflammation of skin, eyes or respiratory tract. Examples: organic solvents, detergents & cement dust, ammonia, chlorine.

•

Corrosive: is a substance the reacts with body proteins and has a penetrating and burning effects on the parts of the body with which they come into contact "skin, eyes, gastrointestinal tract". Examples: phenol, ammonia, sulphuric acid, caustic soda, etc.

•

Toxic: is a substance that has an adverse (poisonous) effect ona target organ or body system. The substance causes its adverse effect when taken in relatively small dose. The effect is either acute or chronic. Example: lead, mercury, arsenic, etc.

•

Carcinogens: are substances capable, often after long periods of exposure, causing disorders to cell growth and may lead to cancer. Example: asbestos, vinyl chloride, chromium.

Exercise 2 In relation to substances

used at work:

-Explain the meaning of the term toxic. -Describe, using an example in EACH case, the difference effects.

between acute and chronic health

Answer 2 •

Toxic: is a substance that has an adverse (poisonous) effect on a target organ or body system. The substance causes its adverse effect when taken in relatively small dose. The effect is either acute or chronic.

•

Acute health effect: an adverse effect resulting from a single or short-term exposure and producing an immediate or rapid effect. Examples: corrosive action, narcosis and primary irritation.

•

Chronic health effect: is an adverse health effect resulting from prolonged or repeated exposures with a gradual or latent and often irreversible effect that may often go unrecognized for a number of years. Example: Cancer, sensitization dermatitis & damage to body organs.

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NEBOSH National General Certificate Exercise 3 In relation to the spillage of a toxic substance from a ruptured drum stored in a warehouse: 1. Identify THREE ways in which persons working in close vicinity to the spillage might be harmed. 2. Outline a procedure in the event of such a spillage. Answer 3 i)

ii)

The ways in which persons might be harmed are: • Direct contact with the skin. • Direct contact with eyes. • Inhalation of fumes or particles. • Ingestion of the materials (direct which is rare and indirect through contaminated hands and ingestion while eating, drinking or smoking at work). • Slipping hazards. • Hazards: depending on the chemical nature of the substances (as flammability for example). The procedure in the event of a spillage: • Isolate or evacuate the area. • Make an initial assessment to determine extent of spillage, type of spillage (liquid, powder, etc.). • Summon help: from emergency services (if this is required). • Deal with the spillage according to its type (for example, in liquid spillage, use absorbent material). • Issue the appropriate PPE to those involved in dealing with the spillage. • Give appropriate first aid and medical treatment to any person who might have been harmed by the initial spillage. • Ongoing health surveillance for the persons exposed to the initial spillage. • Safe disposal of the spilled substance together with any contaminated material.

Exercise 4

A shoe repairer is required to trim soles by hand gluing them on to shoes with a solvent-based adhesive. Outline the measures to minimize the health risks from the tasks. Answer 4 Solvent hazards and ergonomic hazards are the main health hazards. The following are the measures required to minimize the health risks: Measures for solvent hazards: • The use of adhesive of a low toxicity solvent. • The installation of local exhaust ventilation system and ensuring adequate general ventilation. • Ensuring adhesive containers are closed when not in use. • The prohibition of eating or smoking in the work area. • The use of appropriate PPE (gloves, overalls, etc.). • Health surveillance programme to identify the early signs of any ill health effects. Measures for Ergonomic Hazards: The Key Consultancy

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NEBOSH National General Certificate • • • •

Proper work station design to reduce awkward postures e.g., stooping, twisting, overreaching, etc. Good standard of seating and lighting. Reduce constant pressure on the body by varying the task, job rotation or by providing breaks away from the work. Use proper ergonomically designed tool (with a proper handle & kept sharp to minimize the force required, etc.

Exercise 5 Identify the routes of entry of chemical agents into the body: Answer 5 By inhalation: if the chemicals agents is in the form of dust, vapour, fume, gas, etc. it is the most rapid route of entrance. By contact with the skin: chemicals can either: o Irritate the skin causing dermatitis. o Penetrate the skin causing systemic toxicity. By ingestion: can occur directly (by mistake if chemicals are not properly labeled) or indirectly through hands contaminated with chemicals and reaching the mouth during eating, drinking or smoking.

Exercise 6 Outline the advantages and limitations of using a chemical indicator (stain detector) tube to monitor the atmospheric concentration of hazardous substances. Answer 6 The advantages are: • Cheap. • Simple and easy to use. The limitations are: • It requires correct assembly with a properly sealed joint between the tube and bellows pump . • It requires effective counter for the number of pump strokes. • It requires the reagent to be homogeneously distributed in the tube. • Cross reactively of the reagent with other substances can occur. • Reaction in the tube is affected by temperature and pressure: o Change of temperature of 10° C can cause a reaction rate to be doubled. o Change in altitude can cause problems. • The tube has a shelf life so care is required to ensure the tube is currently operative. • Due to reagent complexity, adjustments cannot be made on one spot sample.

Exercise 7 Outline the factors to be considered when managing the risk of exposure to hazardous chemicals at work? Answer 7 •

Factors related to purchasing the hazardous chemicals as: o Purchasing the chemical with the least hazards.

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•

•

•

o Ensuring that material safety data sheet is supplied with the substance. Factors related to transportation of the hazardous chemicals: o To follow instructions including: proper stacking, exclusion of ignition sources, driver training, emergency equipment, etc. o Safety signs including HAZCHEM and TREM cards. Factors related to storage of the hazardous chemicals: o To be stored in a separate external area, which is properly ventilated, adequately lit, of a suitable temperature. o Proper stacking. o Good housekeeping. o Keeping incompatible chemicals apart. o Exclusion of ignition sources. o Stand by-emergency equipment as fire extinguisher, etc. Factors related to use of the hazardous material: o The amount required only to be used. o To provide information to users about nature of substance, it hazards, which type of PPE in required to be used while dealing with it, etc. (this information is included in the substance safety data sheet) Factors related disposal of the substance: o The safest way for disposal of the substance. o The precautions required for disposal workers.

Exercise 8 Identify FOUR forms that an airborne hazardous substances may take? Answer 8 The forms are: o o o o

Dust: are solid particles suspended in the air. It is created by such operations as grinding. Vapour: is the gaseous form of a liquid. It results from heating a liquid. Fume: fine particulate solids resulting from condensation of a vapuor. Gas: is a formless chemical that occupies the area in which it is enclosed.

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NEBOSH National General Certificate Ventilation

Exercise 1 Explain the meaning of the term "dilution ventilation".

Answer 1 •

•

Dilution ventilation is designed to induce a flow of air through a room such that contaminants are sufficiently diluted by the coming air. This is achieved by the use of inlet fans to ensure a supply of clean air. Natural ventilation provided by opening windows or doors is also sometimes included as a form of dilution ventilation, although any flow of air is less certain and therefore it cannot be thought of as an "engineering" solution to an airborne contaminant problem.

Exercise 2 Outline the circumstances

in which the use of dilution ventilation

may be appropriate.

Answer 2 • • • • •

Contaminants of low toxicity. Contaminants of low concentrations. Uniformly evolved contaminants. Low density contaminants (not dust). Areas where there is a non specific point of release.

Exercise 3 List the main components

of a local exhaust ventilation (LEV) system.

Exercise 3 • • • • •

Exhaust Ducting. Purifying Fan and Exhaust

1

inlet (hood). system (filter) . motor. outlet.

2

3

A Local Exhaust Ventilation

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NEBOSH

National General Certificate

Exercise 4 Outline the factors that may effect the efficiency

of a local exhaust ventilation

(LEV) system.

Answer 4 • • • • • • •

Lack of maintenance and testing. Unauthorized alternation. Inadequate design. Overwhelming by increased contaminant levels. Wear or corrosion of fan blades. Blocked filters. Hood being placed too far from the source of the contaminant.

Exercise 5 LEV is to be maintained by law every 14 months, outline the maintenance between the statutory dates.

requirements

Answer 5 • • • • • • • •

To To To To To To To To

check if the filters are blocked. check if there is any obvious damage. check if there is overwhelming by increased contaminant check if there are obvious unauthorized alternations. adjust the hood in the correct angle. lubricate moving parts. check effectiveness of the motor. check blades.

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NEBOSH National General Certificate

Health Hazards

Exercise 1 List THREE Respiratory diseases that could be caused by exposure to dust at work. Answer 1 • •

Asbestosis. Silicosis. Byssinosis. Farmer's lung. Asthma, Bronchitis, Emphysema & Lung cancer.

Exercise 2 Describe the body's respiratory defence mechanisms against atmospheric dust. Answer 2 • • • •

Anatomical structure: Nose and nasopharynx are perpendicular to Trachea and this help reduce velocity of inhaled air by collision with nasopharynx. Respiratory ciliary's escalator: Particles impinge on the mucous lining of respiratory tract and are moved upwards by small hairs or cilia). Reflex actions: as sneezing & coughing to remove any foreign irritating material. Phagocytosis: Is a mechanism by which particles in the alveoli are engulfed and digested (by the aid of phagocytes).

Exercise 3 Outline the control measure that may be used to eliminate or reduce dust in a work environment using practical examples where appropriate.

Answer 3 • • • • • • • •

Elimination of dust (by process change). Substitution (e.g. use of pellets instead of powders). Quality Control (as to reduce the amount of grinding required). Isolation (enclosure of the process e.g. in a glove box). Local exhaust ventilation (LEV): To extract dust close to source. Vacuuming instead of sweeping. Dust Suppression by wet methods. Damping down.

Exercise 4 Explain the meaning of the term "respirable dust"

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NEBOSH National General Certificate Answer 4 -Respirable dust: Is an airborne dust of such a size that it is able to enter the lungs during normal respiration. Dust of 5 microns size or less is respirable. Exercise 5 Outline the ways in which the levels of dust in a workplace can be assessed.

Answer 5 • • • •

Visual signs of dust accumulation. Dust lamps. Direct reading instruments. Sampling using pumps and filters followed by analysis.

Exercise 6 Give TWO occupational examples of diseases from a biological hazard and outline the control measures necessary to reduce the risk of infection from one of theses hazards. Answer 6 Example of occupational diseases from a biological hazards: • Hepatitis • Weil's diseases (Leptospirosis) • Legionnaire's disease. • Anthrax. • Tetanus. Control measures to reduce the risk of infection from Anthrax: • Disinfection of materials infected with Anthrax spores (as wool). • Procedures for disposal of potentially infected materials (as meat, milk, etc.). • Protection of personnel dealing with infected animals (by using the appropriate PPE). • Proper ventilation. Control measures to reduce the risk of infection from Hepatitis: • Immunization of groups at risk. • Use of disposable syringes. • Strict care in blood transfusion procedures. • Procedures for proper disposal of hospital refuse (including syringes & needles). • Boiling of water or water super chlorination. • Medical personnel wear suitable PPE at work. • Health surveillance. Exercise 7 Identify the possible routes of entry of biological organisms into the body. Answer 7 • • • •

Inhalation. Ingestion. Injection. Entry through open wounds.

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Through eyes. Entry through body orifices as: nose, ear, anus, vagina, etc. Through placenta (from mother to baby).

Exercise 8 Outline control measures that could be used to reduce the risk of infection from biological organisms. Answer 8 • • • • • • •

Disinfection for materials or equipment contaminated with the agent. Good personal hygiene. Immunization: vaccination or seroprophylaxis. Chemoprophylaxis. Water control (by boiling or chlorination). Proper disposal of wastes. Use of the appropriate PPE.

Exercise 9 In relation to occupational dermatitis: -Describe typical symptoms. -Identify T\NO substances that may cause the condition. -Outline the specific control measures designed to prevent its occurrence. Answer 9 Typical symptoms of occupational dermatitis: • Skin inflammation. • Dryness of skin. • Cracking of skin. • Rash. Dermatitis Substances: • Solvents as xylene, turpentine. • Cement dust. • Chrome. • Nickel compounds. • Formalin. • Wood dust. Specific control measures designed to prevent occurrence of dermatitis • Elimination of the dermatitis substances (by process change). • Substitution (e.g. use of pellets instead of powders). •

Engineering methods as: • Splash guards to minimize contact with the substance. • Segregation of workers. • Ventilation. • Wet methods for dust.

• • •

Good personal hygiene. Use of barrier and after work creams. Use of specific PPE.

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NEBOSH National General Certificate Exercise 10 Define the term "target organ" within the context of occupational health. Answer 10 Target organ: is the part of the body that sustains an adverse effect when exposed to or contaminated by a particular harmful substances or agent. Examples: -Skin is the target organ of Dermatitis. -Liver is the target organ of Hepatitis. Exercise 11 Outline the personal hygienic practices that should be followed to reduce the risk of ingestion of a hazardous substance. Answer 11 • • • •

Regular hand washing. Restriction of smoking and eating in the workplace. Removing and cleaning contaminated clothes. The use of suitable PPE (as gloves).

Exercise 12 State TWO diseases that may be caused by exposure to asbestos: Answer 12 • • •

Asbestosis. Lung cancer. Mesathelioma.

Exercise 13 Identify where asbestos is likely to be encountered in a building during innovation work. • • • • •

Wall and roof panels. Pipe lagging. Coating as fire resistant encapsulation of metal girders. Insulation materials. Gaskets.

Exercise 14 Outline the factors that may increase risks to pregnant women. Answer 14 • • •

• •

Excessive movement and physical activities. Manual handling activities: as lifting, carrying, pushing, pulling, etc. Dietary Factors: -Lack of essential nutrients in the diet as Proteins, Calcium, and Iron. -Intake of excess fats or carbohydrates. Smoking: whether active or passive. Alcohol and drug abuse.

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Indiscriminate use of legal drugs: without medical advice (Panadol is an example. Exposure of radiation: as Medical X-Ray. Infection by biological agents as German measles virus. Stresses & psychological disturbances.

Exercise

15

Identify the possible indications Answer

of a dust problem in a workplace:

15

•

The process carried out may suggest that dust will be generated e.g.: Grinding.

•

Dust in the atmosphere: may be visible particularly in a beam of sunlight or by the beam from a tyndalllamp. Visual signs of dust accumulation: Deposits of dust might be evident on benches, articles, equipment, etc. Air monitoring: by drawing air through a filter, then analyzing the filter, this will help to detect low dust concentrations. Dust effect on health: as coughing, sneezing, asthmatic symptoms, etc. Impaired respiratory function due to dust inhalation (as detected by health surveillance tests as X-Ray or Pulmonary function tests.).

• • • •

Exercise

16

For each of the following agents, outline the principal health effects and identify a typical work place situation in which a person might be exposed: i. Carbon Monoxide iii. Asbestos ii. Legionella iv. Hepatitis Virus Answer

16

Health Effects i) Carbon Monoxide

ii) Asbestos

*Headache *Drowsiness *Possible Asphvxia *Asbestosis *Lung Cancer *Mesothelioma

& death

Situation

of exposure

*vehicle repair premesis *underground car park *boiler with a defective flue. *Maintenance work for a building where asbestos is contained. *Demolition work.

iii) Legionella

* Legionnaires disease manifested by flu-like symptoms, pneumonia and 15% of cases death can occur.

*Air conditioning system and cooling towers where water droplets are released into atmosphere.

iv) Hepatitis

*Jaundice, fever, abdominal pain. *Iiver cell failure is the serious result.

*Medical and paramedical personnel exposed to needle stick iniuries.

Exercise

17

Identify the possible effects on health that may be caused by working in a hot environment such a foundry.

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NEBOSH National General Certificate Answer 17 -Dehydration: due to loss of fluids. -Heat stress in the form of: • Heat syncope. • Heat cramps. • Heat exhaustion. • Heat stroke. -Heat rash. -Radiant heat burns. -Eye infection or cataracts. Exercise 18 In relation to the ill-health from the use of vibrating hand-held tools: a) Identify the typical symptoms that might be shown by affected individuals. b) Outline the control measures that may be used to minimize the risk of such effects. Answer 18 i) • • • •

The typical symptoms are: Numbness of fingers. Blanching of fingers. Swollen painful joints. Reduction in manual dexterity (things may fall form hands and fine adjustment by hand cannot be achieved).

ii) The control measures are: • Eliminate the risk: by process change to eliminate the need for using vibrating handheld tools. • Reduce the risk: To modify operating procedure so that the pressure upon the tool required by operator is reduced. • Proper selection of equipment (with less vibration). • Good standards of equipment maintenance. • Reducing time of exposure of operators to vibration (this may necessitate recruitment of new staff). • Health surveillance to detect the early sings and symptoms of vibration illness. • Use of appropriate PPE (as gloves to keep hands warm). Exercise 19 A fitter is employed to lay carpet tiles using a solvent-based adhesive in such circumstances. i) Identify the possible effects on health. ii) Outline the control measures that should be considered. Answer 19

• • •

The possible health effects are: Affecting the skin causing dermatitis. If it reaches the eye can cause eye inflammation. If fumes are inhaled it will lead to: o Effects on Central Nervous System. o Dizziness o Narcosis o Respiratory sensitization leading to asthma.

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• • •

The control measures that should be considered are: Elimination: Suggest the use of other alternatives for this process to eliminate the need for using solvent. Substitution: Use materials which are less hazardous. Provision of adequate instructions and training of workers about: o Hazards of adhesive materials. o How to use it safely (safe system of work) o The importance of wearing the suitable PPE. Provision of adequate ventilation in the area. Health surveillance to detect the early signs of exposure to the adhesive. Provision and use of the required PPE (as gloves, goggles, respirators, overall, etc.).

Exercise 20 Outline the possible routes of entry of biological organisms

into the body.

Answer 20 • •

•

•

• •

Inhalation: inhaling air contaminated by disease agents as bacteria, viruses, etc. is a common and rapid way of entrance of biological organisms into the body. Ingestion: which is either: • Direct: through drinking and / or eating contaminated drink or food. • Indirect: through contaminated hand from soiled materials. Injection: through: • Syringes and needles transmitting diseases as hepatitis. • Insects as anopheles causing malaria. Through cuts & wounds: leading to: • Local infection of the wound. • Systematic illness as tetanus. Through the eye: as due to housefly leading to infective conjunctivitis. Through body orifices: as nose, ear, anus, vagina, etc.

Exercise 21 Outline measures that may be taken to help prevent possible effects on health due to working in hot environment as foundry.

Answer 21 The measures required are: • Gradual exposure of workers to heat (to achieve physiological adaptation to heat. • Reducing the time of exposure to heat. • Rest breaks in shady areas. • Barriers or shields between hot source & workers. • Taking workers away from the hot source. • Use of suitable clothes by the workers according to the type of heat: • Minimal clothes if heat is by conduction. • Clothes to reflect heat if heat is by radiation. • Proper ventilation in the area. • Sufficient supply of water and salts to the replace fluids lost. • Provision of information to workers regarding: • Heat hazards. • How to protect the body from heat hazards.

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NEBOSH National General Certificate Exercise 22 Identify the factors that will influence the likelihood of dermatitis occurring in workers handling dermatitic substance:

Answer 22 • • • • • • •

Type of dermatitic substance. Form of dermatitic substance (solid, liquid, vapour, fume, etc.). Concentration of dermatitic substance. The individual susceptibility of workers. Duration & frequency of exposure to the substance. The use of after work creams. The use of PPE.

Exercise 23 Identify the THREE types of asbestos commonly found in a building: White asbestos. Blue asbestos. Brown asbestos.

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NEBOSH National General Certificate

ERGONOMIC

Exercise 1 Outline the factors to be considered

when assessing risks to health of a user of DSE.

Answer 1 • • • • • • • •

Screen characteristics (definition, flicker, reflections, glare, etc.). Design & dimensions of equipment: as desk, chair, keyboard, screen, etc. Adjustability of equipment: as chair, screen, etc. Work space: enough for workers to move during work. Work environment: lighting, ventilation, comfortable temperature, reduction of noise, etc. Software ergonomics: size, colours, delays, etc. Rest breaks: to be provided (this require redesigning task). User characteristics: posture, eye sight, pregnancy, etc.

Exercise 2 Explain the meaning of the term "ergonomics"

Answer 2 *Ergonomic: is designing a task to suit the individual in terms of physical and mental capabilities and the individual's expectations.

Exercise 3 Outline the main factors to be considered in an ergonomic assessment used by an operator of a visual display unit (VDU).

of a workstation

to be

Answer 3 Factors to be considered in an ergonomic assessment of a workstation to be used by an operator of VDU: • Height and position of keyboard & screen. • Design of chair: to be adjustable, with swivel capability, with good lumbar support and to be sloped so that on seating thigh is parallel to the ground". • Adjustability of screen. • Screen characteristics (definition, color, reflection, glare, etc. • Environmental factors: as lighting, temperature, humidity, work space, noise, etc.

Exercise 4 Identify TWO work activities that may gives rise to WRULDs.

Answer 4 • • • • •

Keyboard use (DSE operators). Assembly work. Supermarket check operator. Hair dressers. Cleaners.

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NEBOSH National General Certificate Exercise 5 Outline measures that can be taken to reduce the risk of WRULDs.

Answer 5 • • • •

Redesign task (e.g.: automation to avoid repetitive manual tasks). Work organization (e.g.: job rotation). Equipment design: as keyboard, screen chair, desk, etc. for DSE operators. Proper selection and training of personnel.

Exercise 6 Outline the possible effects on health that may be caused by the poor ergonomic VDU workstation.

design of a

Answer 6 • •

• •

WRULDs: manifested by pain in neck, shoulder or upper limb usually following repetitive tasks as DSE use, assembly work, etc. Eye strain: manifested by diminution of vision, headache, etc. and it usually result from poor lighting in work area, not enough distance away from the screen, reflections, glare, etc. Fatigue and stress: manifested by lack of concentration, irritability, lack of temper, etc. and is usually due to continuous work. (with no breaks). Facial dermatitis: manifested by skin rash on the face and is due to work in a hot illventilated place.

Exercise 7 A computer user has complaint of neck and back pain. Outline the feature associated with the workstation that might have contributed towards this condition.

Answer 7 • • • • • •

Screen position: improper layout of screen or to be at an incorrect height leading to repeated head movement. Chair: is at incorrect height or the seat back incorrectly adjusted. Lighting: poor general or local lighting. Reflections & glare on the screen will force the user to adopt awkward postures to avoid them. Exposure to draughts. The sitting of ancillary equipment (as printer) will also impose awkward movements as twisting.

Exercise 8 Outline the features of a suitable seat for sedentary work.

Exercise 9 • • •

To be adjustable: to suit different users of different heights. To be provided with swivel capability: to allow movement without twisting the body. Adequate lumbar support should be provided by the seat back.

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NEBOSH National General Certificate • • • • • •

Seat should be sloped so that on seating, the thighs are parallel to floor. Seat is to be provided with armrest. Footrest is to be provided (to be used when required). Tilt capability is required in particular circumstances. The base should be stable and depending on the type of activity it may need castors. To be made of material appropriate for the environment.

Exercise 9 Outline the possible health risks associated period of time.

with working in a seated position for a prolonged

Answer 9 • • • • • • • •

Back problems: due to damage in vertebrae or in back muscles. Problems due to static posture: as musculoskeletal disorders of neck, shoulders, arms, elbows, wrists, etc. Effects on joints, tendons & ligaments. Numbness or tingling: due to compression & entrapment of nerves. Circulatory problems as restricted blood flow to limbs that can eventually lead to deep venous thrombosis (DV.T.). Cardiovascular health problems e.g.: elevated blood pressure. Digestive disorders. Obesity and its subsequent health problems.

Exercise10 Outline the symptoms of WRULDs and the factors that will increase the risk of occurrence of WRULDs

Answer 10 *Symptoms of WRULDs: symptoms appear in the upper limb (neck, shoulder, arm, forearm, wrist & hand) and include: • Dull aching pain. • Inability to grasp things securely. • With continued progress of the case, the victim may become incapacitated and lose ability to use the part. *Factors increasing risk of WRULDs: • Repetitive movements: without sufficient break times. • Awkward postures: as stooping, twisting, and overreaching. • Improper selection of the workers for the job: the worker is not fit enough to perform the job. • Improper training of the worker. • Improper design of the workstation: including insufficient space, improper chair, desk, keyboard and screen position, etc.

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NEBOSH National General Certificate

NOISE

Exercise 1 Outline the possible effects on health from exposure

to noise.

Answer 1

•

•

Possible effects on health from exposure to noise: Short-term effects: o Acute acoustic trauma: sudden damage of ear drum due to intense noise levels as in explosion. o Temporary threshold shift: due to fatigue of hearing cells conveying frequencies outside the conversation speech range . Long-term effects: o Tinnitus: ringing in the ear due to intense stimulation of auditory nerve over a period of time. o Permanent threshold shift: due to death of hearing cells conveying frequencies outside the conversation speech range. o Noise-induced hearing loss: due to death of hearing cells conveying conversation speech frequencies. o Fatigue or stress.

Exercise 2 Explain the meaning of the following terms in relation to noise measurement: -dB (A) -Daily personal noise exposure (LEP1 d) Answer 2 •

•

dB (A): is a scale for noise measurement. It is a decibel scale with A-weighting filter. The A-weighting is included in the scale to mimic the response of the human ear in filtering sound. (the human ear is less sensitive to low frequencies). Daily personal noise exposure (LEP1 d): is the continuous equivalent noise level, expressed in dB (A) and measured over an 8 hours working day.

Exercise 3 Outline FOUR types of engineering practical example of each.

controls that may be used to reduce noise, giving a

Answer 3 • •

• •

Absorption: using barriers of porous material (e.g.: foam) to reduce sound energy. E.g.: baffles. Damping: the use of rubber, cork, or similar material to reduce structure borne noise (these materials are to be fitted as pads, stiffening ribs, etc. to reduce vibration) e.g.: machines mounts. Silencing: the use of silencers to suppress noise generated when air, gas, or steam flow in pipes or are exhausted to atmosphere. Isolation: in acoustically-quiet booths.

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Screens: to reduce direct noise transmission. Lagging: can be used on pipes carrying steam or hot liquids. Process change: e.g.: presses instead of hammers, Bolting instead of riveting. Operating rotating and reciprocating equipment as slowly as practicable. Keeping sudden velocity changes in pipe work and ducts to a minimum, Enclosure: surrounding the noise source with sound absorbing material (the effect is limited until total enclosure is achieved). Equipment design: e.g.: use of nylon gears. Proper maintenance & lubrication of machines.

Exercise 4 Explain the meaning of the following terms in relation to noise: -Frequency. -Intensity. Answer 4 • •

Frequency of sound: it refers to pitch of the sound. It is the number of cycles or waves/second and is measured in Hz. Intensity of sound: refers to loudness or amplitude of the sound and is measured in decibels. PQRST=One cycle A= Amplitude (Amplitude is proportional to sound pressure.) = Wavelength. Frequency, or number of cycles per second, has unit in Hertz (Hz).

Exercise 5 Identify the short-term and long-term actions required to tackle noise problem. Answer 5 How to control a noise problem: •

•

Short-term plan: o Turning the noisy machine around may reduce noise levels. o Maintenance and lubrication of the noisy equipment. o Taking the worker away from noisy equipment. o Use of ear PPE (ear plugs or ear muffs). Long-term plan: o Purchasing new equipment with no or very little noise. o Design quieter processes. oUse of:-silencers. -absorptive materials -damping. -screens. o Segregation of workers. o Reducing time of exposure to noise (it may require recruitment of additional staff). o Fitting cut-out devices that trigger if pre-set noise limits are exceeded (noise alarms).

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NEBOSH National General Certificate Exercise

6

Identify noise source, people at risk and control measures -Construction or roadwork. -Bottling plant. -Disco / nightclub. -Telephone call center. Answer

6

Noise 1.) Construction road works

/

Source

Heavy mechanical digging or piling

2) Bottling plant

Noise from filling line

3.) Disco / night club

Noise from the music

4.) Telephone call center

Noise from telephones & general office noise

Exercise

People at Risk

Control

-operators. -& those in immediate vicinity (at high risk). -Members of the public & passers by (at low risk). -workers in the area.

-reduce noise at source (muffle road drill for example). -issue PPE.

-disco jockeys & staff (at high risk). -members of the public (at medium to high risk). -operators with low risk of hearing damage but high risk of effects of stress.

Measure

-restrict access to essential personnel only. -wear hearing protection in the bottling area. -Limit sound levels at source by fitting cut - out devices that trigger if preset noise limits are exceeded. -Limit staff exposure time. -use of appropriate materials for construction, including the use of partitions & furnishing. -work to be interrupted by breaks.

7

Identify the main components Answer

for the following situations:

of sound-level meter:

7

The main components of sound level meter: • Microphone assembly. • Electronic measuring and amplification "including: weighting network, output amplifier & rectifier. • Indicating meter.

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pre-amplifier,

input amplifier,

127

NEBOSH National General Certificate RADIATION

Exercise 1 Explain the term "ionizing radiation". Answer 1 Ionizing radiation: is a type of radiation with high energy potential and general ability to penetrate, ionize and damage body tissues and organs. Example is x-rays. Exercise 2 Outline the suitable measures

for the control of ionizing radiation.

Answer 2 • • • • • • • • •

Reducing time of exposure to ionizing radiation. Shielding (interposing material between radiation source and exposed person): materials of high mass number are chosen for shielding as lead. Distance: increasing the distance between radiation source & those exposed will reduce the radiation dose received. Automatic alarms: if radiation level exceeds certain limits. Monitoring external radiation dose: by use of film badges or thermoluminescent dosimeters. Health surveillance: to detect early sings of exposure to radiation. Proper disposal of radioactive wastes. Wearing the suitable PPE: to prevent radioactive material from being inhaled, ingested or coming into contact with skin. Warning signs to refer to Radiation hazard.

Exercise 3 Identify two type of non-ionizing

radiation giving an occupational

source of EACH.

Answer 3

Type of non-ionizing Ultraviolet-rays Infrared-rays

radiation

Occupational

source

-Physiotherapy -Weldina "arc weldina" -Furnaces -Glass blowing

Radio frequency

-Radio, TV -Dryers, heaters

Microwaves

-Oven, cookers -Radar

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NEBOSH National General Certificate Exercise 4 Identify the health effects associated with the exposure to non-ionizing radiation. Answer 4 Health effect associated with exposure to non-ionizing radiation: • Actinic keratitis (arc eye): due to welding arc and is manifested by eye pain, lacrimation & photophobia. • Eye cataracts. • Erythema or burning of skin. • Premature skin aging. • Skin cancer.

Exercise 5 Identify TVVOworkplace sources of ionizing radiation: Answer 5 Workplace sources of ionizing radiation: • Medical x-ray equipment. • Smoke detectors. • X-ray for scrutiny of welds

Exercise 6 Outline the possible effects on health arising from exposure to ionizing radiation. Answer 6 Possible effects on health arising from exposure to ionizing radiation: • Skin effects: reddening, blistering & ulceration. • Loss of hair. • Eye cataracts. • Sterility. • Radiation sickness (with nausea, vomiting and diarrhoea). • Cell damage including genetic mutation. • Cancers as leukemia, cancer skin, etc.

Exercise 7 Outline the suitable measures for control of non-ionizing radiation. Answer 7 • • • • • • •

Unauthorized people should not gain access to the radiation area. Reduce the time of exposure to the minimal"this require changing system of work". Shielding: to be suitable for the hazard (for example: metal in case of microwaves). Working from a distance. Wearing the appropriate clothes. Wearing the appropriate PPE. Increasing ventilation.

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Maintenance of heaters or dryers can help to prevent leak of stray energy. Reduce time of exposure to sun and use sun creams to act as a shield. Health surveillance to detect early signs of exposure.

Exercise 7 Outline the means of controlling exposure to ionizing radiation. Answer 7 • • • • • • • • • •

Enclosures: by a concrete and/or lead encasement or the use of a glove box. Shielding: by barriers or screens. Segregation: by distance (to increase the distance between radiation source & receivers). Reducing time of exposure of employees to radiation. Ensuring appointment by the employer or radiation protection adviser & radiation protection supervisor to assist in radiation control strategies. Monitoring of exposure to radiation (either environmental monitoring or personal monitoring as for example by film badges). Proper disposal or radioactive wastes. Training and supervision for workers dealing with ionizing radiation as x-ray workers for example. Good personal hygiene practices. The use of the required PPE.

Exercise 8 For each of the following non-ionizing radiations identifies the occupational sourced and state the possible health effects of: I.

ii. iii.

Ultraviolet rays. Infrared rays. Microwave & radio frequency.

Answer 8

Occupational

Source

Health effects

Ultraviolet rays

-Physiotherapy -Arc welding

-Effects on the eye: arc eye (actinic keratitis). -Effects on the skin: *Erythema *Premature aging *Cancer

Infrared rays

-Furnaces -Glass blowing

-Effects on the eye: *Eye cataract -Effects on the skin: *Skin burns (Skin irritation)

Radio frequency

-Radio, T.V. -Dryers, heaters

The major hazards in the absence of pain on exposure thus deep- seated bums may

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NEBOSH National General Certificate occur. Microwaves

-Ovens, cookers -Radar

The major hazards is the absence of pain on exposure thus deep seated burn may occur.

Exercise 9 Enlist categories

of people at risk from UV radiation

Answer 9 • • • • • •

Nurses. Physiotherapists. Printing machine operators. Food and drink irradiators. Laboratory workers. Lighting technicians.

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N EBOSH National General Certificate CONSTRUCTION,

Exercise

DEMOLITION

& EXCAVATION

1

Outline EIGHT precautions that may be taken to ensure the safety of children who might be temped to gain unauthorized access into a construction site. Answer • •

1 Reduce the likelihood of access (by fences, signs, security patrols, etc.). Ensuring safety of the site by: • Filling, covering or fencing excavations. • Removing or boarding ladders. Immobilizing machinery. • Locking away chemicals and tools. • Reducing the height of materials. • Isolating services. • Clearing rubbish & debris.

Exercise 2 Outline EIGHT health and safety precautions demolition work.

that should be taken when undertaking

Answer 2 • • • • • • • • • • •

Barriers & fences to protect from falling debris. Means of preventing falls from height. Identification and isolation of services. Warning signs. Removal of debris from upper levels by the use Elephant trunks. Means of suppressing dust. (e.g.: damping down). The identification and correct removal of hazardous substance such as Asbestos & Lead. The use of properly maintained equipment. Means of preventing premature collapse or the collapse of adjoining properties. Competent personnel. Use of the suitable PPE (e.g.: hard hats, ear defenders, mask, footwear, etc.

Exercise 3 Outline the main precautions

to be taken when carrying out the excavation

work.

Answer 3 • • • • • • • • • •

Detection of services (from plans, use of cable/pipe detectors). Support of sides. Storage of materials and take it away from edge. Stop blocks to prevent vehicles from falling into excavation. Barriers and guard rails. Safe means of access/egress(as ladders). Testing for, and ventilation of fumes. Means of pumping out water. Competent personnel. Use of suitable PPE.

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NEBOSH National General Certificate Exercise 4 Outline the main hazard associated

with construction

work.

Answer 4 •

• • • • • • • • • • •

Chemical hazards: *in different forms (air borne as dust, fumes, vapours, gases from materials as cement powder, organic solvents, etc. liquids as adhesive, tar, etc.). *llInesses linked with construction chemical hazards are; Silicosis, Asbestosis, Lead poisoning, Allergies, etc. Noise: form sources as vehicles, air compressors, cranes, pneumatic hammers, power saws, etc. Vibration: occur with pneumatic hammers, hand tools, etc. Heat: Roofers are exposed to sun, working beside hot engines, heated pots of tar, etc. Radiation: UV rays of the sun is an example. X-ray exposure can occur on checking welds. Falls: due to unstable footing, unguarded holes, slip off scaffolding or ladders, etc. Manual handling hazards: leading to back problems, hernia, etc. Diseases: as histoplasmosis, influenza, T.B., etc. Attacks by animals. Social problems: due to intermittent & constantly changing pattern of life of construction workers. Ergonomic hazards. Electrical hazards.

Exercise 5 Identify the hazards associated with the use of a cement mixer and explain how they should be controlled.

Answer 5 -Manual handling hazard: controlled by the use of mechanical aids as conveyor belts for example, by reducing the weights of the loads, by proper selection and training of handlers, etc. -Ergonomic hazard: controlled by the proper siting of materials to reduce awkward movements as twisting, etc, by proper workstation design, good lighting, etc. -Cement health hazards: "irritant & corrosive" to be controlled by the establishment of safe system of work, good hygienic practices, use PPE as overalls, gloves, marks, etc. -Electrical hazards (if the mixer is electrical): to be controlled by regular inspection and testing of equipment, reducing current voltage, safety at the power supply, safety of wires, cables, etc. and the use of residual current devices, etc. -Hazard of petrol driven mixer to be controlled by measures as: provision of safe storage facilities for the fuel to protect against the risk of fire, training in fueling procedures and the prohibitions of mixer use in confined spaces to protect from exhaust fumes as carbon monoxide. -Noise Hazard: to be controlled by reduced time of exposure & use of ear PPE. -Moving Parts Hazard; require safe system of work so that there is a safe distance away from moving parts.

Exercise 6 Outline the possible causes of a dumper truck overturn on a construction

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site.

133

NEBOSH National General Certificate Answer 6 • • • • • • • •

Overloading of the bucket of the truck. Uneven loading of the truck bucket. Cornering at excessive speeds. Driving across slopes. Driving too close to the edges of embankments Hitting obstructions. Inappropriate tire pressure. Mechanical defects of the truck.

or excavations.

Exercise 7 Identify the design features of a dumper truck intended to minimize the risk of an overturn.

Answer 7 • • • •

The position of the truck center of gravity. The width of the wheelbase. Roll-over protection. The use of seat belts.

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NEBOSH National General Certificate WORKING

ABOVE GROUND

Exercise

LEVEL

1

Prepare a checklist for the safe of use suspended access equipment, such as a windowcleaning cradle. Answer

• • • • • • • • •

1

Condition of cables. Condition of pulleys. Safety of platform boards (SWL). Presence of guardrails. Presence of barriers below work area. Presence of signs. Communication arrangements. Emergency arrangements. Use of PPE as harness.

Exercise 2

Outline the circumstances in which it would be inappropriate to carry out work at height from a ladder. Exercise

• • • • • • •

2

Inappropriate task (e.g.: where two hands are needed or where the work area is large. The equipment or materials to be used are heavy and awkward. Work at excessive height. Work of a long duration where use of ladders will lead to ergonomic body problems. The ladders cannot be secured or made stable. The ladder cannot be protected from vehicles. Adverse weather conditions.

Exercise 3

In relation to safe access for construction work above ground level: -Identify the means of a labeled sketch, the component parts of an independent tied scaffold. -Outline the precautions that should be taken when using a ladder as means of access to the scaffold. Answer 3

The following are the main components of independent tied scaffold: • Upright poles. • Diagonal poles. • Bracing (transverse & longitudinal). • Sole plates & base plates. • Working platform. • Guard rails } • Toe board. } For edge protection. • Ledger & transoms. The Key Consultancy

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Tie to the structure.

The working platform should include: 3 boards --for footing. 4 boards----for footing & storing materials. 5 boards --for general work. 6 boards------ for masonry work. Types of independent tied scaffold: • Light duty: where one platform is used at anyone time e.g.: for painting. • General purpose: where up to 4 platforms can be used. Example for general maintenance. • Heavy duty: where 2 general purpose and two light duty platforms are used. Example for masonry work. The precautions that should be taken when using a ladder as a means of access to the scaffold: • Ensuring suitability of the ladder (regarding type, length, free from damage, etc.). • Securing the ladder. • Use of the ladder on a firm and level ground. • Safe position of the ladder (e.g.: away from traffic routes). • Correct height to base ratio of 4: 1 • Area at base to be kept clear of obstruction, mud, etc. • Platform at top to be kept clear of obstruction. • Ensuring removal at the end of the day. Exercise 4 Outline FIVE factors that may contribute to the collapse of an independent tied scaffold.

Answer 4 The factors that may contribute to the collapse of an independent tied scaffold: • • • • • •

Incorrect design or assembly. Unstable foundations (unconsolidated ground, close proximity to excavations, inadequate sole plates & base plates). Unauthorized alteration (e.g.: removal of ties). Overloading of platforms. Adverse weather conditions (as wind, rain, etc. (rain can affect base stability). Collision by vehicles.

Exercise 5 Outline precautions that could be taken to prevent materials falling from a scaffold whilst work is being carried out. Answer 5 Precautions that could be taken to prevent materials falling from a scaffold while work is being carried out. • The close boarding of platforms. • The provision of toe boards, brick guards, nets, etc. • Good housekeeping to prevent the build-up of materials on the scaffold. The Key Consultancy

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NEBOSH National General Certificate Exercise 6 What are the main hazards associated hazards.

with the use of ladders at work and how to avoid these

Answer 6 The main hazards associated with the use of ladders at work: • Falling hazard: due to slipping or due to insecure ladder (on top and/ or base). • Falling materials over passers by (due to no guarding of area, no signs, etc.). • Electrical hazard: due to placing metallic ladders or wet wooden ladders near power lines. • Collision of ladders by vehicles: if the area is not guarded. • Weather hazards as heat, cold, etc. How such hazards may be avoided: • • • • • • • •

Before using ladder be sure it is free from slippery substances. Guarding of the work area & the use of signs & markings. Make sure ladder is firmly secured (tied at top, secured at bottom or footed by a second person if no more than 3 meters height access is required). Ensure correct slope of ladder (750 angle) corresponding to a ratio of 4:1. Ensure that rungs are level and free from defects. Metallic ladders & wet wooden ladders to be away from power lines. Ensure that ladders are regularly inspected & maintained. Use of the required PPE.

Exercise 7 Describe the features that you would look for in properly elected scaffolding.

Answer 7 The features that you should that look for in properly erected scaffolding are: Correct design with adequate load bearing capacity, adequate foundations, structures should be erected by competent persons, all working platform edges should be adequately protected. (by toe boards, net, handrails, etc.), safe stacking of all materials resting on platforms, no overloading of platforms, working platforms provided with safe means of access, and check inspection records to ensure regular inspection.

Exercise 8 What is meant by "independent

scaffolding"?

Answer 8 Independent scaffolding: is a scaffolding independent of the structure to which access is required. It has many types: • Independent tied scaffold: which are tied to the structure for stability (for example to a window) . • Independent mobile towers: which are towers formed with scaffold tubes and mounted on wheels. They have single working platforms with hand rails and toe boards all around.

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NEBOSH National General Certificate Exercise 9 Outline the precautions

to be taken when contractors

are carrying out work on a fragife roof.

Answer 9 • •

The use of roof ladders or crawling boards. As an absolute minimum, 2 ladders or boards are needed. (never step onto a fragile roof). The fragile area is to be covered and the cover should extend minimum of 1 meter up the roof.

Exercise 10 Describe the precautions

necessary for the safe use of a mobile access tower.

Answer 10 Precautions for safe use of mobile towers: • Erection should be in accordance with manufacturer's recommendation. • Erection, alteration & dismantling to be done by competent persons. • It should stand on a firm level base. • Scaffold tubes to be free from defects e.g.: bent sections. • Proper bracing to prevent twisting and collapse. • The ratio of the minimum base dimensions to the height should not exceed: 1:3 in external use & 1:3.5 in internal use. • The maximal height of tree standing tower is 9.75 meters. • The maximal height of tied tower is 12 meters. • A safe means of access to be provided on the narrowest side of the tower "as vertical ladder attached internally". • Platforms should be properly supported and fully boarded. • Toe boards & guard rails to be provided to prevent falls of workers and/ or materials. • Ladder or stepladders should not be placed on the platform to gain extra height for working. • Tie the mobile tower if: The scaffold is likely to be exposed to strong winds. The tower base is too small for the height. The tower is to be used for operations like: • Grit blasting. • Heavy drilling. • Water jetting. If necessary to lift materials & equipment up . • On using a mobife tower, make sure the castors are locked. • Toe boards & guard rails are to be provided for a platform of more than 2 meter height. The guard rails should be 3 feet above the platform. • Before moving tower, be sure no power lines, obstructions, holes in the ground, etc . • Push the tower from the base.

Exercise 11 Outline the precautions building.

that may be needed when carrying out repairs of the flat roof of a

Answer 11 -Provision of safe access to the roof: by scaffolding and/or ladder. -Edge protection: to prevent falling of people and / or materials.

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NEBOSH National General Certificate -Barriers around the area below the roof to prevent access to the area. -Netting under the roof is sometimes required. -Means of transporting materials to and from the work area. -Protecting workers from weather conditions as sun, rains, winds, etc. -The proper positioning and the safe use of hazardous equipment as: bitumen boilers & gas cylinders. -Special Measures for fragile roof. Never foot on fragile roof directly. Use roof ladder or crawling boards. (these are to be laid across the roof surface). -Wearing the suitable PPE (harness is required in addition to other PPE items as helmet, gloves, safety shoes, overall, etc.).

Exercise 12 Woodwork on the exterior of a two-storey office building is to be repaired during July this year. Preparation work will be carried out from a mobile tower scaffold using below lamps, scrapers and an electrical hand-held sander. 1) Identify the measures that should be adopted in order to protect against the danger of people and / or materials falling from the scaffold. 2) Outline the practical measures to reduce the risk from electricity when using the portable sander. 3) List four other hazards arising from the preparation work and for each hazards, state the possible means of protection.

Answer 12 1) The measures required are: • Erection of scaffold should be in accordance with the manufacturer's recommendation. • Erection of scaffold to be done by competent persons. • Barriers (by tape for example), warning signs and flash light around the work area. • Scaffold should rest on firm level ground. • Scaffold tubes to be free from defects. • Proper bracing to prevent scaffolding collapse. • Castor wheels to be locked while working. • To tie the mobile tower if there are winds or if using heavy materials or equipment. • To be of a safe height: not to exceed: 9.75 meter for mobile towers & 12 meters for tied towers. • Safe ratio of base dimensions to height: 1:3 in internal use & 1:3.5 in internal use. • Use of safe ladders; of sound rungs, with no slipping hazards and the ladder is to properly secured . •. Toe boards and guard rails to be adequate enough to prevent persons and materials falling. • Close boarding of platform. • Never move the tower while people and / or materials are still on platform. • Good housekeeping of materials on the platform. 2) The practical measures to reduce the risk from electricity: • Use certified suitable sander free from any defects with CE quality mark. • Check the cable condition and connections. • Use double insulated cable with impact proof cover/water proof cover. • Use low voltage (11 Qv). • Fit protective device as residual current breaker (CB) or fuse. • If possible use battery powered equipment (to avoid electrical risk). • Earthing: to connect the equipment to earth so that in fault conditions, earth will constitute the least resistant pathway for current. • Proper training and competence of users. The Key Consultancy Ltd 2005: All Rights reserved 139

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Regular inspection and maintenance Proper storage of the equipment. Use the proper PPE.

of equipment.

3) Precautions

Hazard *Heat hazard: due to working under the Sun

*Manual handling hazard: due to lifting paint materials.

*Ergonomic hazards: due to awkward postures during painting.

*Exposure to asbestos & or lead: while removing old paints. *Paint health hazards: as dermatitis, asthma, effects on central nervous system, dizziness, etc. *Fire and explosion: due to hot work or ignition source close to painting.

Exercise

-Reduce time of exposure. -Frequent rest breaks in a shady area. -Wear suitable clothes and wear caps or helmets. -Sufficient fluid & salt intake. -Mechanical handling (as by the aid offorklifts). -Team handling. -Use of proper PPE (as cloth glove). -Training workers about good kinetic handling techniques. -Proper work station design. -Safe system of work. -Workers training & supervision at work. -Task to be interrupted by rest breaks. -Identification & segregation of Asbestos materials. -Use of appropriate PPE (respirator with dust cartridge). -Use of protective clothes and required PPE (as rubber gloves, masks, etc.) -Reducing time of exposure. -Avoid hot work as cutting, grinding, welding, etc. close to painting. -Exclusion of all ignition sources (including smoking) in painting area.

13

Doing repainting work using tower scaffold, outline: 1. The likely hazards of this operation. 2. The required control measures to avoid risks from this operation. Answer

13

Tower scaffolds are towers made with scaffold tubes and having a single working Platform accessible by a ladder. It is commonly used for painting and simple maintenance jogs on buildings. It can be used mobile as it is or ties to the building: The likely hazards are: • Health hazards due to exposure to paint: leading to dermatitis, asthma, effects on central nervous system, dizziness, etc. Also lead hazards due to removal of old paints. • Ergonomic hazards: due to awkward posture & movements during painting. • Manual handling hazards: due to carrying heavy cans & other instrument. • Heat hazards: due to working under the Sun . • Falling hazards: due to: • The use of unsafe ladder. • Improper boarding of the platform. • Inadequate toes boards, guard rails & bracing.

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• •

Collapse of the tower due to many reasons (improperly erected tower, doing unauthorized alterations, use of defective scaffold tubes, or erection on non firm & non level ground). Collision with power line & other obstructions. Falling of materials (if toe boards & guard rails are inadequate).

The precautions: • Erection of the tower scaffold should be in accordance with manufacturer's recommendations. • Erection, alteration and dismantling of tower scaffold to be done by competent persons . • Tower scaffold should stand on a firm level base. • Scaffold tubes to be free from defects. • Proper bracing to prevent twisting & collapse. • Base dimensions to height should not exceed: 1:3 in external use & 1:3.5 in internal use. • The maximum height is: 9.75 meters for free mobile tower & 12 meters for tied tower. • Tower should never be moved while people or materials are still on the platform. • Platform should be properly supported & fully boarded. • Toe board & guard rails to be provided to prevent falling of workers and / or materials. • To make sure that castors are locked. • Before moving tower, be sure no power lines / obstructions or holes in the ground. • Training of painters about how to work safely. • Use protective clothes and PPE during painting (as gloves, suitable overall, face shield, respirator). • Good supervision of the painting process . • Good communication. • Stand-by first aid and emergency services.

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NEBOSH National General Certificate Waste

Exercise 1 Outline the issues that should be considered on dealing with waste collection & disposal.

by an organization

to ensure safe system of work

Answer 1 For collection of waste, consider the following: • • • • • • • •

Risk assessment to identify the hazards associated with waste collection. Collect waste at regular basis and avoid its accumulation. Use waste containers of sufficient number, of a suitable material and of adequate size and to be positioned in accessible locations with signs referring to it. Avoid overfilling of waste containers. Waste container to be easily opened and to be securely closed to avoid attraction of flies, insects, etc. Proper selection and training of workers dealing with waste collection. Health surveillance for workers dealing with waste collection. Provision of required PPE for workers involved in waste collection. For disposal of waste, consider the following:

• • • • • • • • •

Use the method of disposal suitable for the waste type (as incineration for papers, etc. and composting for food waste). Assess the chemical and effective load of the waste. Monitor the environment (pre and post disposal). Waste disposal work permit is required for some special wastes. Safe method for dealing with by-products of waste disposal (as dumping of ash resulting from incineration). Use of property trained personnel for waste disposal. Health surveillance for disposal workers. Stand-by emergency equipment for events as fire, etc. Use of the required PPE by disposal workers. Regulations

• •

concerned

with waste are:

Waste Management Licensing Regulation Special Waste Regulation 1996.

1994.

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NEBOSH National General Certificate Control Measures

Exercise 1 While dealing with any question hierarchy of control measures:

asking

for "Control

Measures":

always

remember

the

Answer 1 • • • •

Elimination Substitution. Engineering controls (including work permit) Administrative Controls o Reduced time of exposure. o Training. o Safety signs. o First aid and emergency measures. o Health surveillance. o Use of PPE.

Exercise 2 The key items as how to deal with any hazard question:

Answer 2

•

• • •

• • • •

• •

•

According to the work activity performed: If the work is outdoor, consider: Weather hazards as heat, cold, rain. Bite by animals, snakes, insects, etc. If work is at the roadside, consider: Collision by vehicles. If the work is dealing with grass or other plants consider: insect bites. If the work is dealing with water (as fro cleaning canals), consider: Drowning hazard. Trench foot hazard. Leptospirosis (Weil's disease) If the work is requiring manual handling (as lifting painting cans, cleaning material, etc, etc.) consider: manual handling hazard. If doing tasks as painting, floor cleaning, keyboard use, assembly work, etc., consider: Ergonomic hazard. If an equipment is used, consider: Equipment hazards (mechanical & non mechanical) If the equipment used is petrol driven, consider: Carbon monoxide hazards. Nitrogen oxides hazards. If the equipment used is electrically operated, consider: electrical hazards. If a chemical is used (as a solvent), consider: Health hazards as dermatitis, asthma, effects on central nervous system, dizziness, etc. Safety hazards as fires, explosives, etc. If the work is at height, consider: Falling hazard of individuals. Falling hazard of materials.

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•

If there is a risk of infection (as on dealing with refuse, sludge, etc.) consider: biological hazards . If working in a confined space, consider: Atmospheric hazards (as lack of oxygen or toxic frames). Entrapment. Biological hazards. Equipment hazards. Manual handling hazards . On doing repainting, consider: Hazards due to removal of old paint: as lead exposure. Hazards of painting (as health hazards, fire, explosion, manual handling, ergonomic and weather hazards).

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