NEBOSH IGC Summary – week 2
Element 1:- Workplace hazards & risk control Hazards to pedestrians Slips, trips and falls (on same level) Falls from height Objects moving, flying or falling Collisions with moving vehicles Causes of slips, trips & falls (accidents on walkways or Staircases) 1- Old age 2- Sensory impairment e.g. Poor eyesight 3- Unsuitable foot wear 4- Slippery surface e.g. polished floor 5- Spillage e.g. oil on floor 6 During the floor cleaning 7- Poor lighting / limited vision because of the dust or fog 8- Uneven surface 9- moving from one kind of floor surface to another 10Carrying heavy / large loads 11Poor physical condition / ill health / consciousness problems 12Rainy weather without suitable drainage system 13Poor housekeeping / Obstacles on the walkway (e.g. protrusions) 14Bad organisation or layout of the work place 15Lack of attention / distractions 16Alcohol & drugs 17Fatigue & exhaustion 18Loose / Untied shoe laces 19- Poor emergency procedures: people crowding, panicking & rushing to evacuate 20Not using the handrails 21Not keeping 3 points of contact 22Walking backwards e.g. banks man 23Broken steps / different heights 24Running, jumping & Horseplay
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Working at height Hazards of working at height Fall of people Fall of objects Collapse Overturn Contact with overhead services Precautions & Control measures: - Avoid working at height by using long tools or machines - Reduce height as much as possible - Reduce duration & frequency of working at height - it is - Using proper working platform, carrying out pre use inspection & regular maintenance - PPE e.g. safety harness, fall arrestors & helmets with strap - Edge protection & Safety net - Ensure Safe access & egress to the work place Precautions & Control measures of working on ANY roof: The above precautions PLUS: - Using crawl boards - Locating & covering the lights on the roof (if any) Hazards of ladders Fall of people Fall of objects Collapse Overturn Contact with overhead services Precautions & Control measures: - Ladder resting with both feet on a levelled firm floor - Distance between the ladder & the wall in the ratio 1 : 4 - Rested & fixed against solid surface - Suitable for the task, approved, inspected & in good condition - Fixed & secured at the top - 3 steps extra length at the top - Only one person at a time - Keeping 3 points of contact - PPE e.g. gloves,safety shoes, coveralls & helmets with straps - Clean firm non-slip steps
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Should only be used as a mean of access NOT as a working platform
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Independant tied Scaffold Draw and label key parts of an independent Tied Scaffold
Control measures & precautions -
Designed, erected, inspected, altered & maintained by competent certified people Should be suitable for the job & certified Inspected before each shift & after any accident, incident or adverse weather conditions Avoid overloading or exceeding SWL Use of guard rails & toe boards Stop work in adverse weather conditions e.g. strong wind it is PPE e.g. helmets with strap & safety harness
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Mobile Tower Scaffold Hazards Fall of people Fall of objects Collapse Overturn Contact with overhead services Precautions & control measures Above precautions for independant tied scaffold PLUS: -
Positioned on firm ground Use of outriggers to broaden base & locking the wheels Braced & tied to permenant structure People and materials removed before moving
Mobile Elevated Work Platforms (MEWP) Hazards - Fall of people - Fall of objects - Collapse - Overturn - Contact with overhead services - Crushing between carrier and a fixed structure or inbetween the Scissors lift Accidetns, Collapse or overturning of MEWP caused by Equipment failure Unsuitable ground conditions Defective or unused outriggers Unsuitable MEWP or in bad condition (lack of maintenance) Overloading Struck by load or vehicles Incompetent operator Interference with controls by others Strong wind / storms Precautions & control measures = Same like Tower scaffold PSTC (www.pstconsultant.com,
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Suspended access cradle Hazards Fall of people Fall of objects Collapse Overturn Contact with overhead services Crushing between carrier and a fixed structure Precautions & control measures = Same like Tower scaffold
Excavations Main -
hazards Fall of people Fall of objects e.g. tools or fluids causing flooding Collapse of the excavation (Caving) Overturn of vehicles close to edge Contact with underground services (electrical cables, gas pipes, sewage, telephone) Access and egress (being a confined space: Difficults access & egress, Hazardous atmospheres Contamination (sewage, spores) Type of soil Removal of soil Undermining foundations
Precautions & control measures Plan the job using location maps Locate & avoid underground cables e.g. CAT (cable avoidance tools) Issue permit to work Safe digging procedures (follwoing SSOW) Use competent workers – it is PPE e.g. coveralls, helmets & safety shoes Improving evironmental factors such as lighting & ventillation Ensure safe access & egress
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Demolition Methods of Demolition Hand-held tools Machine Chemical agents (Explosives) Hazards of Demolition Safety hazards: Fall of People Fall of objects Premature collapse Contact with underground & overhead services Fire & Explosion Electricity Health hazards; Gases, fumes and vapours Asbestos Lead Silica Noise Vibration Ionising radiation Biological hazards Control measures & Precautions: Pre-demolition surveys & area maps Safe method of demolition & safe organized demolition sequence Competent workers Evacuating near buildings if needed PPE e.g. helmets, reflective vest , steel toe safety shoes Safe access & egress Issue pertmit to work & other legislative documents Site Precautions for children - Fencing & barriers all around the site - Security guards & patrols - Monitoring the area with CCTV Cameras - Warning signs & Posters - Visit schools & provide information to the people in charge - Take children to site on visits (arranging class trips to the site) - Lock the vehicles & remove the keys PSTC (www.pstconsultant.com,
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Remove ladders & prevent access to scaffolds Lock away hazardous chemicals Cover holes & excavations Reduce heights of materials
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Element 2: Transport hazards and risk control Hazards of vehicles including fork lift trucks (General) - Overturning - Overloading - Loss of loads - Collision with pedestrians, buildings or other vehicles - Fire and Explosions Additional hazards of electric – battery fork lifts - Hydrogen gas released during battery charging - Inhalation of fumes - Corrosives leading to burns - Electricity problems - Manual handling of battery during recharging - They are quiet (People may not hear them coming) Procedures to follow when parking fork lift trucks - To be parked in the designated parking area (on a levelled surface not Blocking Walkways or exits) - Switch off engine, lights, radio, etc... - Remove the key & keep it with the responsible person / place. - Put gears (controls) in neutral position. - Apply the handbrake and the wheel chock to prevent rolling away - Forks to be resting on the floor - Mast slightly tilted forward -Surround the forklift with cones & barriers to prevent trips over the Forks. Driver selection Suitable age Medical examination & Routine medical checks at regular intervals Assessment after prolonged absences Competence (KATE, Proper qualifying training & Refresher training)
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Safety of pedestrians in vehicle moving areas Precautions to prevent collision between vehicles and pedestrians Precautions to ensure safety of vehicles operation -
Setting & enforcement of site traffice rules, proper signs & Floor marking Segregation between vehicular route & pedestrian route Suitable designated parking areas Proper environmental conditions e.g. adequate lighting & reduced noise Avoid sharp or blind bends Vision panels in doors or transparent doors Sufficiently wide entrances, gateways & traffic routes Vision aids e.g. CCTV cameras or mirrors on vehicles & at blind corners Setting speed limits for cars e.g. 20 km/h Designated marked crossing points for pedestrians FOPS ROPS PPE e.g. steel toe safety shoes & High visibility jackets Driver training & qualification Using ground guides in reversing (Signallers / Banks men) Avoid reversing if possible e.g. One-way systems, drive through parking, circling the vehicles Reversing alarms (audible & visual) Refuges & Barriers in loading docks
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Element 3:- Musculoskeletal hazards & risk control Ergonomics: The relation & interaction between the work & the worker; how to fit the work to the worker. In other words, Ergonomics is the study of designing equipment and devices that fit the human body, its movements, and its cognitive abilities. Causes of WRULDs Repetitive movements of fingers, hands or arms Twisting movements Squeezing Hammering Pushing, pulling or over reaching movements Symptoms Numbness & tingling in fingers Pain in hands or arms Restriction of joint movement Soft tissue swelling Examples for WRULDs Tendonitis Epicondylitis Carpal Tunnel Syndrome Risk factors to consider Force exerted Duration & frequency of operation Repetition of movement without rest or recovery time (frequent breaks) Awkward Posture Vulnerability e.g. smokers or existing medical condition Constraints on space Environment (low temperature) Control measures: Improve or fix above plus:Automate or mechanise task Use correct tools and equipment it is PSTC (www.pstconsultant.com,
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Health effects of DSE use (Display Screen Equipment) Upper limb disorders (WRULDs) Eye and eyesight effects Epilepsy Facial dermatitis Electro magnetic radiation effect on pregnant women Fatigue, stress & Discomfort Workstation requirements Adequate lighting (general & local lighting) Minimum noise Suitable legroom Suitable screen at eye level Keyboard at suitable distance Suitable software Organized work surface Footrest if necessary Document holder if needed Suitable work chair Characters of the Suitable Seat Good lumbar support Comfortable material with good width and depth Adjustable (Ability to adjust seat back and height) Stable base (5 legs or 5 points of contact with the ground) Ability to swivel Provision of arm rests Other control measures: - Adequate breaks (regular & mini breaks) - Eye sight testing & medical checkup - it is
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Manual Handling Manual Handling Injuries External: Cuts, bruises (Contusions), abrasions, Burns Internal: Fractures, slipped disc (Disc prolapsed), Muscle Sprains, Tendon tears, ligaments tears, joint dislocation, Hernia Activities at risk - Handling excessive loads - Repetitive handling without adequate breaks or recovery time - Prolonged handling of loads especially if including excessive: Bending, stooping, twisting & over reaching Factors affecting the manual handling: Load Weight, Size, Shape Rigidity, Difficulty to grasp Stability (centre of gravity) Sharp edges Hot / cold surface Contents (hazardous or not) Individual Gender Physical capability, energy, Stamina, Height, pregnancy or illness Competence (Manual handling Training, physical abilities & experience) PPE Task Number of boxes needed to be lifted Duration & frequency of the job Vertical & Horizontal distance where the load will be lifted to. Job rotation / sufficient rest or recovery (breaks) Team lifting Any need for excessive pulling, pushing, twisting, bending & overreaching. Environment Constraints on posture / Space Floor condition & type of floor surface Level of housekeeping Hot/Cold/ humid conditions or strong wind Environmental factors e.g. Lighting
remember LITE
Hierarchy of control to reduce manual handling injuries: - Avoid manual handling (automate or mechanise the job by using forklifts, cranes, hoists or conveyors) - Team lifting - Mechanical aids e.g. trolley - Dividing the load into smaller packages (less weight) - Reduce duration & frequency of manual handling tasks - PPE e.g. gloves & safety shoes - it is (manual handling training , etc..) - Follow safe system of work (safe handling technique) Kinetic Handling Technique (safe way of lifting a box) - Assess the load - Check the route - Get as Close as possible to the load with suitable feet position - Ensure secure & firm grip with PPE - Lift the load keeping the back straight & bending only the knees - Keep the Load close to the body while walking - Walk Smoothly avoiding jerky movements - Put down the load then slide into position
Mechanical lifting equipment -
Forklifts Conveyors Cranes Hoists
CONVEYORS Hazard Entanglement Drawing in Sharp edges Items jamming conveyor Fall of objects Riding or crossing conveyor
Control measures & Precautions Guards, No loose clothing Pop out rollers, nip guards Edge protection, eliminate edges Adequate design, guards Edge guards, barriers Bridges, complete enclosure
Impact with objects Noise Manual handling Electricity
Helmets Ear plugs Mechanical handling & it is Maintenance & good selection
Hazards of CRANES Fall of people Fall of objects Collapse Overturn Contact with overhead services Types of CRANES Mobile Tower Gantry Overhead Gantry Types of HOISTS Chain hoist Goods hoist Patient hoist (rescue hoist) Safe use of Cranes (Precautions for ANY safe mechanical lifting) - Suitable certified crane - Suitable certified, color coded lifting accessories & correct slinging technique - Competent crane operators & banks men using good means of communications & agreed signals - Suitable ground conditions (firm levelled surface) - Use of outriggers - Clear pathway avoiding any obstructions - Avoiding overhead services such as power lines - Segregation of working area by barriers & warning signs so one could walk under the load - Visual & Audible alarms to warn that lifting is taking place - Load to be lifted vertically and to correct height & kept near ground when travelling - Ensure load is secured, balanced & guided by tag lines - Avoid exceeding of the SWL - Ensure Good visibility with adequate lighting & reduced nosie - Ensure suitable weather conditions and stop the lifting operation in adverse weather conditons e.g. strong wind - PPE e.g. Gloves, steel toe safety shoes and reflective jackets - When the load is placed on the ground; Release the tension first to avoid load tackling
Element 4:- Work equipment hazards & risk control Suitability of the work equipment - Initial integrity - Purpose for use - Place of use Precautions for maintenance Work - Issue permit to work if the job is high risk or non-routine as example if the whole body or the whole arm of the worker will be inside the machine - Isolation of power source (disconnection & lock out tag out) - Dissipation of stored energy e.g. release stored pressure, earthing for electricity or leaving the hot surface to cool down - Segregation of the work place by means of barriers & warning signs Safe means of access - Use suitable PPE e.g. safety shoes, coveralls and safety glasses - Ensure that all workers doing the job are Competent enough - Ensure safe environmental conditions e.g. adequate lighting & good ventilation - Emergency procedures / SSOW Mechanical Hazards of Machinery (ENTICE) Entanglement Traps (drawing in – crush / shear) Impact Contact (stab/puncture – cuts – abrasions – burns – etc.) Ejection Draw labelled diagram of each one
Entanglement
Traps (Drawing in)
Traps (Crush / shear)
Contact (puncture / stab)
Contact (abrasions)
Imapct
Contact (cuts)
Ejection
Non-Mechanical Hazards of Machinery Chemical / biological hazards Ergonomics / Manual Handling Electricity / Noise Fire / Explosion Vibration / Radiation / Ultra violet radiation Temperature extremes Dust and fumes Office machinery: - Photocopier and document Shredder Manufacturing / Maintenance Machinery: Bench top grinder and Pedestal drill Agricultural Machinery: - Cylinder mower & trimmer Retail Machinery:- Waste Compactor & Checkout Conveyor Construction Machinery:- Cement Mixer, Circular Saw & petrol chainsaw Machinery Hierarchy of Controls (FIAT) Fixed guards Interlocking guards, Adjustable guards & Automatic sweep guards. Appliances (Holders / Push Sticks) & Protection devices (Trip device, safety trip wire, photo electric cells, pressure sensitive mats and two hand control system) Training, Information, Instruction, and Supervision (it is) and PPE Fixed Guards:- A physical barrier, kept at its place at all times, has no moving parts, not linked to the machine controls and usually requires a tool to remove it. Advantages Minimal maintenance Only defeated by deliberate act Visual inspection is enough May protect against other hazards e.g. noise, dust, ejection of materials
Disadvantages Not linked to machine controls No protection when removed Full access to dangerous parts when removed More difficult to remove: not practical when frequent access required Tends to be left unfixed when frequent access required May hamper visibility
Interlocking Guard: - Linked to the machine controls so that the worker can’t gain access when the machine is in a dangerous condition ALSO opening the guard causes the machine to become safe Advantages Allow safe access for feeding materials (frequent opening) to use Convenient Less likely to be deliberately defeated Speeds up operations
Disadvantages Increase the complexity of the machine Difficult to test and maintain May need a brake or time delay May fail to danger Regular maintenance required
Adjustable Guards the length of the guard could be adjusted (changed) according to the length of the material being used, two types of this guard: 1) Manual (fixed) type and 2) Automatic type Automatic Sweep Guard Where the guard pushes the worker away from the danger zone Protection Appliances:- such as holders & push sticks Protection devices:- such as Trip device, safety trip wire, photo electric system, pressure sensitive mat & two hand control device iT is: on how the machine is operated safely, how & when to be maintained, who is authorized to use it, etc. PPE: -
such as coveralls for chemical splash & entanglement goggles for ejected material ear plugs for noise steel toe safety shoes for crush injuries hair nets for hair entanglement GLOVES should be banned near rotating shafts
Element 5:- Electrical Safety Hazards of Electricity Be SAFE Burns Shock Arcing Fire Explosions
Burns
Internal burns to the body organs & external burns to the skin 3 degrees Melting any worn metals e.g. watches or rings Shock electric shock (Electrocution) Factors affecting / influencing severity of electrical shock - Voltage - Current (amperes) - Time - Conductivity or resistance of the body - Current path through the body - Nature of contact (grip or touch) - Individual factors (age, general health condition, children with thin skin) Emergency action on finding someone in contact with electricity - Isolate the supply if possible or move the person away from the source of electricity using an insulating material e.g. wood - Call for help - Check ABC - Apply CPR if needed - Treat burns if any - Remain with casualty till emergency services arrive Arcing When electricity has sufficient potential to jump across insulating material such as air
Fire Causes of Electrical Fires Inadequate circuits Overloading electrical circuits Incorrect fuses Damaged insulation Loose connections Using flammable materials too close to electrical equipment Overheating of cables on coils Inadequate ventilation for electrical equipment & cables Explosion Ignition of gas Secondary Effects of Electricity Falls from height Throw off (away from the source of electricity) Unintentional movement of machine Failure / De-activation of control measures & security systems Loss of information Tripping over cables Loss of corporate reputation Health effects of Electricity on the body External burns to the skin Internal burns to the body organs Irregular heartbeat (Fibrillation) Stopping of the heart (cardiac arrest) Stopping of breathing (Respiratory paralysis) Muscular contractions Damage to nervous system Precautions to ensure safety of portable electrical equipment Ensure competence of workers : KATE PPE e.g. insulating gloves & safety shoes Avoid overloading circuits Regular preventive maintenance for the electrical equipment including thermographic tests Safe correct routing of cables to avoid being ran over by vehicles, dragged over rough surface, trapped in machinery or getting in contact with chemicals or hot surface Pre use visual inspection to ensure good insulation and that wiring and casing are free from damage Using approved suitable equipment & in good condition Avoid home made or temporary connections
Always pull the plug NEVER the Lead & Avoid continous flexing Use the suitable protective systems such as
Protective systems: Fuse:- A weak link designed to melt, breaking the circuit at excessive currents Advantages Cheap and readily available
Protects equipment
Disadvantages Does not protect the individual from shockto operate Slow Inaccurate Unsuitable or wrong fuse may be used Easy to override Could need tools to replace
Circuit Breakers:- Electromagnetic device which perform the same function as fuses i.e. break the circuit at excessive current although slightly faster
Advantages Automatically switch or trip under fault conditions No tools to reset Not easy to override No reset until fault cleared Protects against overload
Disadvantages Does not protect the individual from shock
Earthing:- Electricity will always try reach earth and earthing means providing a path to earth lower than the human body Advantages May prevent indirect shock by providing a very low resistance path Readily identified
Disadvantages Specialist testing and maintenance, professional installation Protection defeated if removed
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Isolation:- The disconnection and separation of the electrical equipment from every source of electrical equipment in such a way that the disconnection and separation is secure (Lock out & Tag out) Advantages Safest option as it eliminates electricity May be physically locked off
Disadvantages May isolate other equipment May be reconnected unless locked off Prevents live fault finding
Battery operated tools:- Using battery instead of electrical wires Advantages Minimal risk during normal use Range not restricted by cable No trailing cable = No tripping hazards or overheating
Limited power output
Precautions need to be followed during mains charging Heavier More expensive
Disadvantages Limited battery capacity
Reduced voltage systems:- By reducing the voltage present system the consequences of electrical shock can be greatly reduced Advantages Available voltage difference is 55V ac injury is highly unlikely Colour coded cabling system for easy recognition
Disadvantages Specialist equipment required for 110 V Lead from supply to transformer at higher voltages and will need protection with a RCD
Residual Current Device (RCD):- It compares the current flowing into the system with the current flowing out. When the level differs by a preset value the RCD will open rapidly and interrupt the supply
Advantages Rapid and sensitive
Difficult to defeat
Easy to use, test and reset
Cannot be reset with a fault on the circuit
Disadvantages May isolate crucial equipment if one RCD covers a number of distribution points, e.g. freezers Mechanical device, which could fail Only protects against earth leakage faults (no overload protection)
Double Insulation:- Covering live parts by two separated layers of insulation Advantages Two layers of insulation prevent user contact with any live No earth required
Disadvantages Physical damage may defeat double insulation No earth provided in double insulation extension leads, therefore defeats protection if used with
Element 6:- Fire safety The fire triangle: Fuel (Combustible material) Heat (Source of ignition) Oxygen (air) Causes of fire Arson Smoking & smokers’ materials Oil/gas heating equipment and portable heaters Unsafe storage of flammable materials Use of flammable liquids or gases in unsuitable areas Hot work: welding, cutting, etc. Mechanical heat (Sparks/friction) PLUS causes of electrical fires page 19
Flash point:- The temperature at which gas & vapour will ignite momentarily by an external source of ignition e.g. spark Fire point:- The temperature at which gas & vapour will sustain a flame when ignited by an external source of ignition e.g. spark Auto-Ignition (Self ignition):- The temperature at which gas & vapour will ignite without any external source of ignition. Methods of Heat Transfer Direct burning:- The flame and a combustible fuel are in direct contact and the fuel heats up and eventually ignites. Radiation:- Heat is radiated through the air causing heating of a materials at a distance from the fire. Conduction: Heat travels within solid material from the hot part to cooler part Convection:- Hot air current rises up to replace cooler air , causing the build up of hot and unburned gases under ceilings etc. and allows fire to spread from one room to another.
Classes of fire A B C D
Carbonaceous material (Combustible solids) EXAMPLE: Wood & paper Flammable liquids EXAMPLE: Alcohol & Petrol Flammable gases EXAMPLE: Butane, methane & propane Metals EXAMPLE: Aluminium & Magnesium F Cooking oil EXAMPLE: Vegetable oil & animal fats Electrical Classified according to the source of ignition rather than fuel Source
Types of fire extinguishers For For For For For
class A class B class C class D class F
Water, Dry powder or Aqueous Film Forming Foam (AFFF) ry powder, AFFF or CO2 D Dry powder or CO2 pecial powder or dry sand S Wet chemicals
For Electrical Dry powder or CO2
Wet Chemicals (potassium acetate, carbonate, or citrate) extinguishes the fire by forming a soapy foam blanket over the burning oil and by cooling the oil.
In the UK the use of Halon gas is now prohibited except under certain situations such as on aircraft and in the military and police
Precautions to prevent & control risk of fire AND to minimise the risk to people in the event of fire -
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Eliminate / reduce the amount of flammable materials Segregate fuel & ignition sources Good level of housekeeping to prevent accumulation of waste paper Good security measures to prevent arson Safe storage of flammable material Compartmentation: dividing the building into isolated units (compartments) by means of fire doors & fire walls so that any fire in any of these units will be contained there & won’t spread to the rest of the building Proper regular maintenance for all types of equipment Electrical safety it is & following SSOW Suitable fire alarms & fire detectors. Fire marshals to guide the employees during the evacuation Suitable means of fire fighting such as water sprinklers, whose reels and fire extinguishers Unobstructed means of escape with reasonable travel distances, fire doors, exit signs, Emergency lighting & illuminating signs Assembly points (Muster points) Regular drills & practices on evacuation
Precautions to ensure safe evacuation in the event of fire - Adequate fire detection equipments e.g. smoke detectors - Good means of raising alarms (visual & audible) - Automatic contact with the emergency services & fire department - Roll calls - Safe evacuation plan. - Special consideration for disabled people, pregnant women, etc. - Regular drills & practices on evacuation - Unobstructed means of escape with reasonable travel distances fire doors, exit signs, Emergency lighting & illuminating signs - Muster point / assembly point (clearly identified & proper location) - Closing the windows & fire doors after leaving - Adequate fire fighting equipment such as: Fire extinguishers, sprinklers, hose reels - Fire marshals & fire wardens helping in the above
Element 7:- Chemical & biological health hazards & risk control Respiratory defences (Body defences against dust) - The hair in the nose acting as a filter to purify the air from the dust particles - wetness of the nose (mucus) so the dust would stick to it & will be trapped and will go no further inside the lung - The change of direction to the larynx so the dust particles in the air would stick to the nasal wall - Sneezing and coughing which would expel the dust outside the respiratory system - Turbulent motion of the air in the nose and the centrifugal force which will throw the dust to the sides sticking to the mucus - The hair cells in the respiratory tract (Ciliary escalator) pushing the dust upwards till it reach the throat where it could be removed from the body - The immunity system of the body: White Blood Cells (WBC) in the alveoli - Fibrosis of the lung: isolating the affected non-functioning part from the rest of the healthy lung - Tears and blinking of the eyes (not part of the respiratory defences) Digestive defences (Body defences against ingested substances) - Digestive juices & enzymes, the useful bacteria and the strong acid (HCL) which will destroy the harmful substances inside the stomach. - Vomiting & diarrhoea which get rid of the toxins and the harmful substance out of the body. - Smell & taste protecting the person from eating or drinking harmful substances or bad food. Skin -
defences Sweating: Cooling down the skin and killing harmful organisms Keratin: Forming the protective hard layer of the skin Melanin: responsible for the pigmentation of the skin, more melanin makes the skin darker providing more protection from the sun and ultra violet light Sebum: the oily substance secreted by the skin to prevent it from dryness Hair: protecting and filtering the skin Sensory serves: the sense of touch in the skin Blisters, rash and inflammation to fight any infection of the skin
Other defences - Tears & Blinking of the eye - Pain - Hormones e.g. Adrenalin Types of Dermatitis: 1- Irritant / Contact 2- Allergic / Sensitive Symptoms: - Irritation of the skin, Inflammation, Blisters, rash, swelling, redness, hotness, Dryness and cracking of skin, and in severe cases: Ulcers & infections Protective measures against dermatitis (Precautions) Eliminate the substance Substitution by a less hazardous one Reduce duration & frequency of exposure to the substance Medical checkup for the workers Good hygiene practices PPE e.g. gloves and coveralls Barrier creams Extractor fans & LEV it is Dose-response relationship All substances are poisons; there is none which is not a poison; The right dose differentiates a poison and a remedy. Target Organs: The part / parts of the body which could be affected by an external substance Example: Inhalation of asbestos fibres will affect the lung causing cancer (asbestosis) SO the target organ of the asbestos is the lung Other examples: Mercury, Lead brain & nervous system Ammonia eyes, skin & lungs Organic solvents liver, skin & lungs Also see examples page 34
Local effect: The effect of the substance happens at the same point of contact
Systemic effect: The effect of the substance happens away from the point of contact
Acute effect: Adverse health effects resulting from single or short term exposure to a large dose of the harmful substance producing an immediate or rapid effect, it is usually reversible. EXAMPLE: Alcohol intoxication due to consuming large amount of alcohol in short time. Chronic effect: Adverse health effects resulting from prolonged & repeated exposure to a small dose of the harmful substance producing a gradual & latent effect which usually stays unrecognized for several years, it is usually irreversible EXAMPLE: Liver damage (cirrhosis) caused by consuming small amount of Alcohol for many years. Occupational Hygiene & Health hazards 1- Identification of health hazards 2- Measurement of health hazards 3- Assessment of health hazards 4- Control of health hazards 1- Identification of health hazards: -
Forms of chemical agents: Dust: Total inhalable & Respirable dust (0.5 – 7.0 micron) Fume Mist Smoke Vapour
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Forms of biological agents: Fungi Bacteria Viruses
Routes of entry into the body (chemical agents) - Inhalation - Ingestion - Direct entry (open wounds) - Injection - Absorption
Classification of Hazardous Substances Irritant: Non-corrosive substances which through immediate, prolonged or repeated contact with skin or mucous membrane may cause inflammation (Dermatitis) Example: Petrol, cement, weak acids & alkalis Corrosive: Substances which on contact with living tissue may destroy it by burning Example: acids (sulphuric acid) and alkalis (caustic soda) Harmful: Substances which if swallowed, inhaled or penetrated the skin may cause damage to health (cause diseases – ill health) Example: Petrol, cement Toxic: A poisonous substance which may cause acute or chronic damage to health or DEATH Example: Arsenic Very Toxic: A poisonous substance which may cause acute or chronic damage to health or DEATH even in low quantity Example: Cyanide Carcinogenic: Substances which cause disorders to cell growth that may lead to cancer (malignant tumours) Example: Asbestos Mutagenic: Substances which cause changes to the chromosomes (DNA / genetic material) leading to hereditary defects in the offspring of the affected person. Example: Bromine & Benzene Teratogenic: Substances which cause harmful effects to the embryo (baby) inside the uterus of the pregnant woman. Example: Drugs & medications
Material Safety Data sheet (MSDS) = Information on hazard data sheet
1234-
Identification of the substance & Manufacturers’ information Composition & information on ingredients Hazard identification First aid measures 5- Fire fighting measures 6- Accidental release measures 7Handling & Storage 8- Exposure control & Personal protection 9- Physical & Chemical properties 10- Stability & Reactivity 11- Toxicological information 12- Ecological information 13- Disposal consideration 14- Transport information 15- Regulatory information 16- Other Occupational Exposure Limits (OEL) •
Long-term exposure limit (LTEL) 8 hour
•
Short-term exposure limit (STEL) 15 minute Limits are expressed in: – ppm (parts per million) for gases and vapours 3 – mg/m for airborne particles such as dust and fume
2- Measurement of health hazards: THREE survey techniques:1) Initial appraisal: Gathering information such as OEL, details of the substances used, people affected, types of hazards, risks, and precautions; from different sources such as MSDS, manuals, experts, etc. 2) Basic survey: Qualitative observations: Smoke tube & Dust lamp Quantitative observations: Stain tube detector (Grab sampler)
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Diagram of Chemical stain tube detector (Grab Sampler)
Glass tube
Direction of flow
READ
1
Fused tip
Pre-layer
Advantages Low cost Takes little time Immediate result Little training needed Information during spillage Good for coarse indication
2
3 5 1020
Porous granules, e.g. silica gel, chemical reagent
Fused tip Scale divisions
Disadvantages Inaccurate Positioning of tube affects reading Only a snap shot Inefficient Chemical use only Substance specific
3) Full survey: Direct reading instruments: such as Carbon dioxide gas analyzer Indirect reading instruments: Passive (by diffusion) such as radiation badge / film badge Active (powered by mechanical pump) such as H2S detector
3- Assessment of health hazards: Risk assessment (5 STEPS AS USUAL)
4- Control of health hazards: Eliminate: remove the substance, or avoid the activity or process e.g. pressure jetting a blocked drain instead of using dissolving chemicals Reduce: reduce the risk by -
reducing the duration / frequency of exposure to the hazard substituting the material with a less hazardous one e.g. using water based paint instead of solvent based paint OR using granular material instead of powder
Isolate: -
Total Enclosure of the machine inside a glove box Worker to be isolated inside a ventilated control room
Control -
Engineering Control: LEV & adequate maintenance for equipment Administrative control: Change the work pattern or method, job rotation, adequate breaks, good levels of Hygiene and housekeeping & providing the needed it is
PPE: - Respiratory protection such as breathing apparatus to protect from chlorine or ammonia - Hand & skin protection such as gloves to protect from detergents or solvents - Eye protection such as goggles to protect from corrosives or ammonia - Protective clothing such as chemical splash suits to protect from acids & biological agents - Barrier creams Discipline
Labelled diagram of Local Exhaust Ventilation (LEV)
LEV becomes inefficient because of:- Failure of operators to use it properly - Lack of proper maintenance - Unauthorised modifications - Incorrect settings - Hood damaged or not well positioned - Blocked / damaged ducts - Full / damaged dust collection bags - Blocked / damaged filter - Wear & tear of fan blades - Increased contaminant level - Poor design of the LEV (inadequate capacity) Checks / inspection: opposite of above
Examples of chemical agents (hazardous substances) & Target Organs
Ammonia Strongly corrosive alkaline colourless gas with a pungent odour. Affecting the skin, eyes & the lungs. Leading to eye irritation, dermatitis, inflammation of the lungs and in the large concentrations can cause blindness and fluid in the lungs (emphysema) Eye protection and respiratory protection are essential. Asbestos Affecting the lungs causing Asbestosis (Lung cancer) Carbon Dioxide CO2 Colourless and odourless gas which is heavier than air. Affecting the lungs increasing the rate of respiration and high levels depress the rate of respiration leading to unconsciousness and even death Carbon Monoxide CO More toxic than CO2, Colourless and odourless and tasteless gas. Found where incomplete combustion occurs e.g. boilers, vehicle exhausts Affecting the lungs & the blood casuing headache, drowsiness, flushed “pink” appearance and ultimately asphyxiation and death Chlorine A greenish toxic gas with a pungent smell. Affecting the eyes & the respiratory system casuing severe irritation. Lead A heavy, soft and easily worked metal. Can enter body by eating contaminated food or by breathing fumes or dust. Affecting the brain & the nervous system casuing acute lead poisoning Resulting in nausea, headaches, nervous problems and in severe cases causing death. Organic Solvents These dissolve other substances & are also used as cleaning & degreasing agents. They are volatile & evaporate quickly at room temperature so their vapours can be breathed easily. Affecting the skin, nasal passages, throat, lungs, eyes, & the liver. Effects may be headaches, nausea, dizziness & loss of consciousness and in extreme cases leading to death.
Isocyanates Organic compounds widely used in industry for products such as spray painting of vehicles and production of polyurethane rubbers and foams. Affecting the nasal passages, throat & the lungs leading to lung Inflammation & asthma. Silica Found in sand, granite & glass Affecting the lungs as breathing silica could lead to serious lung disease “silicosis” Dust Affecting the respiratory system causing asthma, bronchitis, emphysema and conditions such as asbestosis or Silicosis if the dust contains asbestos or silica. Dust -
Identification: Visual signs of dust in the air or deposited on surfaces or clothes Results of monitoring using dust lamps or smoke tube Poor visibility or excessive tears & blinking of the eyes respiratory problems: coughing, sneezing, breathing difficulty Maintenance problems e.g. abnormal blocking of filters
Control measures for dust: - Elimination of dusty operation (outsourcing) - Bringing pre-formed components - Substitution e.g. granules or paste instead of powders - Enclosure of the dusty operation or machines - Extractor fans & Local exhaust ventilation (LEV) - Vaccuming instead of sweeping - Damping down the dust by spraying water - Reduce duration & frequency of exposure to dust - Reduce duration & frequency of the dusty operations - Reduce number of workers exposed to dust - Respiratory protective equipment e.g. dust mask - Medical check up & Health survillance with medical treatment for any health problem - it is
Biological Agents Leptospirosis (Weil’s disease) Bacterial infection transmitted to humans by ingesting contaminated rat urine. The most common source is in construction sites, water sports, river water, swimming pools, sewers, etc. Symptoms: Flu like symptoms (Fever, sneezing, coughing & headache), Pneumonia, meningitis & Jaundice. Fatal in 20% of the cases (Attacks the kidneys & liver) Precautions & Control measures: pest control, covering damaged skin, it is, good hygiene & housekeeping Legionella (Legionnaire’s disease) Bacterial infection transmitted to humann by inhaling airborne bacteria found in water sources such as air conditioning systems, cooling towers, stagnant water etc. Symptoms: Flu like symptoms (Fever, sneezing, coughing & headache), Pneumonia & difficulty in breathing Fatal in 20% of the cases. Those at greatest risk are smokers or old people with chest problems. Precautions & Control measures: Temperature control and monitoring, avoiding stagnation & avoiding “dead legs” in pipe work, biocide treatment and effective cleaning and maintenance. Hepatitis A, B and C Viral inflammation of the liver caused by viral infection transmitted through ingesting food contaminated with faeces (hepatitis A) Or by blood & body fluids (hepatitis B & C) Symptoms: Inflammation of the liver, fever, nausea, malaise & jaundice. Precautions & Control measures: Vaccination, disinfection, it is, Avoiding sharp implements, Proper disposal of contaminated waste and good hygiene practices.
Routes of entry into the body (Biological agents) - Inhalation - Ingestion
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Direct entry (open wounds) Injection
Precautions for safe storage of waste - Choosing a Suitable location - Sufficient storage area - Labelled & individual containers - Ensure storage area is well secured - Store different types of waste separately - Never store incompatible waste together - Select appropriate containers - Keep quantities of waste to a minimum - Protect waste from the elements - Protection form adverse weather conditions - Avoid contamination of general waste with hazardous materials
Element 8:- Physical & psychological hazards Noise:
is any unwanted sound
Frequency:- Measuring the pitch / tone of the sound waves, measured in cycles per second or Hertz (Hz) Human range is 20 Hz – 20 KHz Intensity:- Measuring the loudness / amplitude of the sound waves measured in decibel (dB) Safe limit is 80 dB Rule of 3 Every 3 dB increases means doubling the intensity i.e. 83 dB is double the intensity of 80 dB Health effects of noise Acute Stress, Irritability, nervousness , increased heart rate and insomnia Temporary threshold shift Temporary tinnitus Trauma e.g. Burst eardrum Blast deafness
Chronic
Permanent threshold shift (Noise Induced Hearing Loss) Permanent tinnitus Presbycusis
Factors affecting the risk from Noise - Frequency in Hz - Loudness in dB - Duration & frequency of exposure to noise - Use of PPE - Distance between the source of noise & the person exposed to it - The nature of the place Noise control measures / precautions Source: Eliminate or reduce the noise from the source by - Improving the design of the machine - Damping
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Isolation Proper maintenance
Path: Prevent/reduce transmission of noise through air or structures by using - Screens and barriers - Enclosure - Absorption - Silencer The Person: - Increase the distance between the worker & the source of noise - Reduce the duration & frequency of exposure to the noise - it is - PPE such as ear plugs & ear muffs
Hand-Arm Vibration Health Effects Acute: Numbness & Tingling in the hands and extremities Chronic: - Permanent Numbness & Tingling - Blanching of the fingers (Vibration White Fingers) - Swollen painful joints - Reduction in manual dexterity - Reduction in the sensation of touch Risk -
Factors Frequency of the vibrating tools ( in Hz) Force exerted Duration & frequency of exposure Low temperature Individual factors e.g. age & health condition
Control Measures for hand-arm vibration - Automate or mechanise the job to elimination the use of vibrating tools - Select the suitable tool with low vibration - Reduce the degree of vibration as much as possible - Select ergonomically designed equipment - Proper maintenance of equipment
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Reduce the force exerted & the strength of grip with work equipment Reduce the duration of exposure to the vibration Health surveillance & treatment of any medical problem Use PPE such as Gloves and heated pads it is on the nature of risks
Work in Hot & Cold environment Physiological effects of heat Stress (in foundries, glass works & laundries) Skin burns Cataracts Dehydration Heat cramps Raised heart rate Headaches Confusion & Loss of concentration Vomiting Fainting Sun stroke & Heat stroke Physiological effects of cold Stress (cold stores, food preparation area, big freezers & open air during winter) Lowered heart rate Hypothermia Shivering Confusion & Loss of concentration Frost bite Increased risk of strains & sprains Risk factors - Body activity & health condition - Type & amount of clothes - Duration & frequency of exposure - Ambient temperature & weather conditions - Source of heat / cold temperature Control measures - Acclimatisation - Health surveillance & medical checkup - Hot / cold drinks - Reduce duration & frequency of exposure - Temperature control - PPE e.g. insulating clothes PSTC (www.pstconsultant.com,
[email protected], 0514303707,03355033003-4
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PSTC (www.pstconsultant.com,
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Radiation Non-Ionising Type Infrared Lasers Microwaves Ultra-violet Radio waves
Use in Industry Heating and brazing Cutting, Bar code readers Food preparation, Signal transmission Welding Radar and communications
Health effects of non-ionizing radiation Burns Erythema (Reddening of the skin) Cataract Arc eye Retinal burn Temporary sterility Risk • • • • • • •
factors & Control measures of non-ionizing radiation: Duration & frequency of exposure Distance between the source & the worker Shielding it is Proper maintenance & inspection of equipment (source) PPE, e.g. eye protection Skin creams
Ionising Radiation Type Alpha Beta Gamma X-Ray
Use in Industry Smoke detectors & anti static devices Thickness testing & sterilisation of material Non-Destructive Testing & Radio therapy NDT & Radio diagnosis
Health effects of ionizing radiation Acute health effects (high dose) Erythema (Reddening of the skin) Radiation sickness (Nausea & Vomiting) Hair loss
Chronic health effects (small dose) Carcinogenic effect (Cancer) Mutagenic effect (Hereditary defects) Teratogenic effect
Diarrhoea Death
Sterility , erythema & cataract Death
Risk -
factors & Control measures ofionizing radiation Duration & frequency of exposure Distance between the radioactive material & the people Proper shielding (Lead or thick concrete) Using suitable PPE e.g. radiation suit Correct disposal of radioactive materials half life of the radioactive material Good hygiene practices it is Monitoring exposure using film badges & Geiger counters
Violence at work Verbal abuse / threats AND Physical attacks Internal AND external violence
Occupations at risk Taxi drivers , Health care professionals, Schools, Cash transactions Delivery/collection of money, Representing authority e.g. policemen & enforcement officers Control measures - it is: on absorbing anger, how to recognise aggressive behaviour & how to deal with it wisely - Providing information on delays - Proper queue management - Welcoming environment & nice decor - Checking visitors’ credentials (IDs) - Safe & secure design of workplace e.g. wide counters, coded locked doors & physical barriers - Security officers & CCTV cameras - Good means of Communication & alarm systems - Regular removal of cash from the workplace - Avoid Lone working; safe precautions for lone workers - Reporting, recording and investigating violent incidents - Zero tolerance of aggressive behaviour
Stress Physical Effects Headaches Dizziness Aching neck and shoulders Skin rash Prone to infections Raised heart rate & Increased blood pressure Diabetes Heart disease Stomach & mouth ulcers
Psychological effects Increased anxiety Reduced concentration Irritability & nervousness Panic attacks & Sudden mood changesto cope Inability Reduced work output / performance Increased use of alcohol, drugs, pain killers & tobacco Insomnia (Poor sleep patterns)
Causes of stress: 1. 2. 3. 4.
5. 6.
7. 8.
Culture of the organisation: how it approaches work-related stress, e.g. communication, consultation, staff support systems, and working hours; Demands: workload too high or too low, shift work and unsocial hours, excessive overtime, and exposure to violence and bullying; Control: how much control the person has in the way they do their work, e.g. work planning, use of acquired skills, repetitive or monotonous work; Relationships between employees: physical violence, threats or verbal abuse e.g. repeated shouting and swearing, malicious gossip; unjustified picking of faults, prevention of career development; sexual harassment; & discrimination due to gender, race or disability; Change: how organisational change is managed and communicated in the organisation, e.g. new technology, restructuring, redundancies, and unclear objectives; Role: job insecurity, fear of redundancy, being unclear about roles, responsibilities and expectations, conflicting roles, e.g. the conflict of different job demands such as working for more than one manager; Individual: skills not matched to the task, inadequate training, unclear job description, and fair and open feedback on the work and role, illness, financial worries, family commitments; and Environment: inadequate lighting, problems with glare, cramped or untidy working conditions, security problems, extremes of temperature and / or humidity, inadequate ventilation, draughty conditions, high noise and vibration levels, inadequate welfare facilities and poor weather conditions for those working outside.
Identification of Stress Stress within the organisation may be identified by:
informal observation & conversation with workers & supervisors; performance appraisal with an opportunity for open discussion of problems; monitoring of attendance records and conducting ‘return to work’ interviews; sickness absence / ill-health trends; reduced productivity of the employees High staff turnover.
The end of week 2
GOOD
LUCK
Please Turn Over
Examination rules & tips -
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Each question MUST be answered on a separate page (subsections of the same question should be answered in the same page, ONLY a NEW question should be on a new separate page) The number of the question must be mentioned in the box at the top of the page All answers must be Specific , complete & meaningful sentences The handwriting should be CLEAR enough Use the regular blue pen & in the drawings use a pencil In General: 8 mark question = 8 points answer, 6 mark = 6 points etc. In General: the answer of 8 mark question should be about half a side of A4 page and the answer of 20 mark question should be about one side & half of A4 pages The exam starts at 9:00 am SHARP Bring your passport or ID The exam is 2 hours ; If your mother tongue is not English (according to the nationality registered in the exam) you will be given extra 30 minutes, so the exam will be 2 & half hours instead of 2 hours but ONLY if you bring a non-technical bilingual dictionary (regular book not electronic one) Nothing else is alowed as it’s a closed book exam
Time of the exam is enough but just enough , don’t waste your time Read the question 3 times carefully before starting the answer If you run out of time , answer in the form of list Don’t cross any answer as there’s no negative marking As much as possible; Structure your answer into separate headings e.g. external & internal / short term & long term etc. Action Verbs in exam questions: o
Explain, Describe or Outline: Give a detailed word picture ; Give a clear account of, or reasons for o List / Identify / Give / state : Select & name: Provide without explanation nor details o Define: Provide a generally recognised or accepted definition PLUS an appropriate example o Sketch: Draw a labelled diagram (using a pencil)
