January 2011
Examiners’ Report NEBOSH International Diploma in Occupational Health and Safety (Unit IC)
Examiners’ Report NEBOSH INTERNATIONAL DIPLOMA IN OCCUPATIONAL HEALTH AND SAFETY Unit IC – International workplace and work equipment safety JANUARY 2011
CONTENTS
Introduction
2
General comments
3
Comments on individual questions
4
2011 NEBOSH, Dominus Way, Meridian Business Park, Leicester LE19 1QW tel: 0116 263 4700
fax: 0116 282 4000
email:
[email protected]
website: www.nebosh.org.uk
The National Examination Board in Occupational Safety and Health is a registered charity, number 1010444 T(s):exrpts/J/J-C 1101
EXTERNAL
DW/DA/REW
Introduction
NEBOSH (The National Examination Board in Occupational Safety and Health) was formed in 1979 as an independent examining board and awarding body with charitable status. We offer a comprehensive range of globally-recognised, vocationally-related qualifications designed to meet the health, safety, environmental and risk management needs of all places of work in both the private and public sectors. Courses leading to NEBOSH qualifications attract over 25,000 candidates annually and are offered by over 400 course providers in 65 countries around the world. Our qualifications are recognised by the relevant professional membership bodies including the Institution of Occupational Safety and Health (IOSH) and the International Institute of Risk and Safety Management (IIRSM). NEBOSH is an awarding body to be recognised and regulated by the UK regulatory authorities:
The Office of the Qualifications and Examinations Regulator (Ofqual) in England The Department for Children, Education, Lifelong Learning and Skills (DCELLS) in Wales The Council for the Curriculum, Examinations and Assessment (CCEA) in Northern Ireland The Scottish Qualifications Authority (SQA) in Scotland
NEBOSH follows the “GCSE, GCE, VCE, GNVQ and AEA Code of Practice 2007/8” published by the regulatory authorities in relation to examination setting and marking (available at the Ofqual website www.ofqual.gov.uk). While not obliged to adhere to this code, NEBOSH regards it as best practice to do so. Candidates’ scripts are marked by a team of Examiners appointed by NEBOSH on the basis of their qualifications and experience. The standard of the qualification is determined by NEBOSH, which is overseen by the NEBOSH Council comprising nominees from, amongst others, the Health and Safety Executive (HSE), the Confederation of British Industry (CBI), the Trades Union Congress (TUC) and the Institution of Occupational Safety and Health (IOSH). Representatives of course providers, from both the public and private sectors, are elected to the NEBOSH Council. This report on the Examination provides information on the performance of candidates which it is hoped will be useful to candidates and tutors in preparation for future examinations. It is intended to be constructive and informative and to promote better understanding of the syllabus content and the application of assessment criteria. © NEBOSH 2011
Any enquiries about this report publication should be addressed to: NEBOSH Dominus Way Meridian Business Park Leicester LE10 1QW Tel: 0116 263 4700 Fax: 0116 282 4000 Email:
[email protected]
2
EXTERNAL
General comments
Many candidates are well prepared for this unit assessment and provide comprehensive and relevant answers in response to the demands of the question paper. This includes the ability to demonstrate understanding of knowledge by applying it to workplace situations. There are always some candidates, however, who appear to be unprepared for the unit assessment and who show both a lack of knowledge of the syllabus content and a lack of understanding of how key concepts should be applied to workplace situations. In order to meet the pass standard for this assessment, acquisition of knowledge and understanding across the syllabus are prerequisites. However, candidates need to demonstrate their knowledge and understanding in answering the questions set. Referral of candidates in this unit is invariably because they are unable to write a full, well-informed answer to the question asked. Some candidates find it difficult to relate their learning to the questions and as a result offer responses reliant on recalled knowledge and conjecture and fail to demonstrate any degree of understanding. Candidates should prepare themselves for this vocational examination by ensuring their understanding, not rote-learning pre-prepared answers. Common pitfalls It is recognised that many candidates are well prepared for their assessments. However, recurrent issues, as outlined below, continue to prevent some candidates reaching their full potential in the assessment.
Many candidates fail to apply the basic principles of examination technique and for some candidates this means the difference between a pass and a referral.
In some instances, candidates are failing because they do not attempt all the required questions or are failing to provide complete answers. Candidates are advised to always attempt an answer to a compulsory question, even when the mind goes blank. Applying basic health and safety management principles can generate credit worthy points.
Some candidates fail to answer the question set and instead provide information that may be relevant to the topic but is irrelevant to the question and cannot therefore be awarded marks.
Many candidates fail to apply the command words (also known as action verbs, eg describe, outline, etc). Command words are the instructions that guide the candidate on the depth of answer required. If, for instance, a question asks the candidate to ‘describe’ something, then few marks will be awarded to an answer that is an outline.
Some candidates fail to separate their answers into the different sub-sections of the questions. These candidates could gain marks for the different sections if they clearly indicated which part of the question they were answering (by using the numbering from the question in their answer, for example). Structuring their answers to address the different parts of the question can also help in logically drawing out the points to be made in response.
Candidates need to plan their time effectively. Some candidates fail to make good use of their time and give excessive detail in some answers leaving insufficient time to address all of the questions.
Candidates should also be aware that Examiners cannot award marks if handwriting is illegible.
The International Diploma in Health and Safety is taught and examined in English. Candidates are therefore expected to have a good command of both written and spoken English including technical and scientific vocabulary. The recommended standard expected of candidates is equivalent to the International English Language Testing System (IELTS) level 7 (very good user). It is evident from a number of scripts that there are candidates attempting the examination without the necessary English language skills. More information on the IELTS standards can be found at www.ielts.org
3
EXTERNAL
UNIT IC – International workplace and work equipment safety
Section A – all questions compulsory Question 1
A sewage drain has collapsed and it is necessary to inspect the damage prior to its repair. The inspection requires entry into a confined space 10 metres deep. Outline the possible risks to those entering the sewer.
(10)
In answering this question, candidates were expected to outline possible risks such as those associated with the presence of gases and vapours either toxic and/or flammable and an atmosphere that was deficient in oxygen which could lead to asphyxiation and/or suffocation; working on slippery surfaces and the presence of pipes, cables or tools which could result in falls; the possibility of the sudden ingress of water with the danger of drowning; the presence of chemical or biological contaminants either on the surface water or in the sludge deposited in the sewer with the risk of contracting illnesses such as Weil’s disease; working in a restricted space with low headroom which might lead to musculoskeletal injuries; thermal issues such as heat exhaustion that might occur when working in high temperatures; coming into contact with sharps with the resultant needle stick injuries; and the ever present risk of entrapment which could be caused by the collapse of the sewer. Answers were generally to a reasonable standard. Some candidates did not read the question with sufficient care and referred to hazards rather than risks and though reference to control measures was not required a few mentioned these often without detailing the risks they were supposed to control. Many candidates failed to provide the detailed required for an outline answer.
Question 2
Outline what should be considered when preparing a scheme for the systematic examination, testing and maintenance of portable electrical appliances.
(10)
In answering this question, candidates should have first considered the importance of producing an initial inventory of the equipment to be examined and tested including its source such as in-house, contractors or workers and ensuring that each item was provided with a unique means of identification. That completed, it would then be necessary to determine the appropriate type and frequency of inspection for each item based on factors affecting the level of risk, such as the type of appliance, any protective systems provided such as earthing, double insulation, or reduced voltage, the age and usage of the appliance, the environment in which it was used such as in a corrosive atmosphere where more frequent testing may be required, and the experience and competence of the user. Additionally, historical data and manufacturer’s recommendations would need to be taken into consideration. Finally, criteria for each type of examination and test would have to be laid down which would include issues such as the competence of the tester, the calibration and maintenance of test equipment, the format of records to be kept on the results of the tests and examinations and systems to identify and take out of use equipment that was found to be faulty. Better answers included reference to published guidance from the appropriate regulator or professional institute.
4
EXTERNAL
Many candidates listed the parts of the equipment that should be checked and tested rather than what should be considered in the preparation of a scheme for examination and testing. A few identified faults such as loose wires and defective plugs while there were others who did not appear to possess the technical knowledge to deal with this type of question.
Question 3
Members of the public have been injured when collecting baggage from a baggage conveyor at an airport. (a)
Identify typical mechanical hazards when the conveyor is in use.
(4)
(b)
Outline the control measures that should be in place to reduce the risk of injury from the mechanical hazards.
(6)
For part (a), candidates should have identified mechanical hazards such as trapping between the interlaced parts of the conveyor bed, between moving items of baggage or between the lip and trapped baggage; abrasion hazards from coming into contact with the moving belt; impact hazards from coming into contact with moving baggage which might have been inadequately stacked or in attempting to replace items that had fallen from the belt; and the possibility of entanglement when items of clothing or jewellery become caught in the moving conveyor. It might have been expected that most candidates would have had experience of collecting baggage from a conveyor at an airport and indeed most were able to identify the typical mechanical hazards from the moving conveyor though some were under the impression that dangerous parts were always exposed, others identified non-mechanical hazards such as electricity and noise while a few dealt with the hazards connected to the use of roller conveyors. For the second part of the question, control measures that should be in place include the control of the speed of the conveyor; a reduction in gaps in the belt at critical points such as turns; the replacement of worn conveyor parts; the use of E-stops in the event of blockage or other emergency; the use of photo-sensitive detectors; using a klaxon or strobe warning lights in the case of an inadvertent start-up; using workers to assess the conveyors for blockages and to assist passengers when this is seen to be necessary and providing signage advising caution when removing baggage from the conveyor, on the action to be taken in the event of a blockage and warning against placing hands or feet on the conveyor. Whilst the hazards may have been identified for the first part of the question, outlining the control measures proved to be more difficult with some candidates suggesting the impracticable such as prohibiting passengers from wearing loose clothing or jewellery and others demonstrating a lack of realism by suggesting that passengers should be kept away from the conveyors.
5
EXTERNAL
Question 4
Environmental pollution is a major concern in many industrial processes. A number of alternative strategies are available to organisations to manage these risks. Give the meaning of: (a)
Integrated Pollution Prevention and Control (IPPC);
(4)
(b)
Best Practicable Environmental Option (BPEO);
(3)
(c)
Best Available Techniques (BAT).
(3)
For part (a), candidates were expected to include that Integrated Pollution Prevention and Control applies to industrial installations and its main aim is to achieve a high level of protection of the environment taken as a whole. It takes into account the whole performance of the plant and as it is ‘integrated’ includes emissions to air, water and land, the generation of waste, the use of raw materials, energy efficiency, noise, the prevention of accidents and the restoration of the site upon closure. For part (b), a good answer would have included that Best Practicable Environmental Option is the option which provides the most benefits or least damage to the environment taken as a whole at an acceptable cost and in the long as well as in the short term. The option includes a range of methods such as kerb side recycling and green composting. Best Available Techniques applies to certain polluting installations and its aim is to avoid or reduce emissions and their impact on the environment as a whole. It takes into account the balance between costs and benefits to the environment so that the greater the environmental damage that can be prevented, the greater the cost of the techniques that must be provided. ‘Available’ are those techniques that are readily procurable by any person, while ‘techniques’ included plants, systems, processes, monitoring measures and staff. Many candidates struggled in answering this question and the responses provided were limited with most showing little knowledge of the subject area.
Question 5
A motor vehicle repair workshop has installed a new electrically powered, compressed air system. Outline the factors to be considered in developing a suitable planned preventative maintenance programme.
(10)
The first stage in the development of a maintenance programme would be to consider the design life and expected reliability of the system, the manufacturer’s specifications, the pattern of usage whether constant, periodic or only as a standby and the anticipated fault pattern based on experience gained in using similar equipment. Consideration could then be given to further factors such as the need for routine operations such as belt tightening, lubrication and filter changes, the need for regular replacement of critical parts to prevent breakdown and the availability of the component parts, the operations that would be required at specific times to counter corrosion, wear and fatigue and any statutory requirements or those required by insurance companies.
6
EXTERNAL
Additionally, thought should also be given to the available occasions when ‘shut-down’ maintenance might be performed; to the particular safety aspects of maintenance while equipment was running; to the need for safe systems of work such as permits or electrical isolation; and to the availability of staff with the necessary skills and competencies to carry out the work. A written scheme of maintenance might then be prepared which would include the safety precautions that should be taken and the arrangements for recording details of the work carried out such as the results of inspections, the defects found, and the remedial action taken such as the replacement of parts. Answers were limited with many candidates producing a list of items to be checked and maintained rather than the factors to be considered in the development of a programme for planned preventive maintenance. Some considered the siting of the equipment and the training of workers while others did not recognise that a compressed air system is a pressure system and accordingly the condition of critical parts and safety aspects in carrying out maintenance were of paramount importance.
Question 6
A diesel engine is being used to power a machine in a potentially flammable atmosphere. (a)
Identify the sources of ignition from the diesel engine.
(4)
(b)
Outline the protection that should be applied to the engine to minimise the risk of an explosion.
(6)
In the first part of the question, candidates were asked to identify possible sources of ignition from a diesel engine. They should have referred to flames or sparks from the exhaust and inlet systems, sparks arising from the engine’s electrical system, sparks caused by the presence of static electricity, through over speeding or overloading of the engine and from friction or the surface temperature. Answers were to a reasonable standard though there were some candidates with the misconception that spark plugs were likely sources of ignition and that the fuel was highly flammable. Part (b) required an outline of the protection that should be applied to the engine to minimise the risk of explosion. An initial protection measure would be the fitting of flame and spark arrestors to prevent flashback to atmosphere if flammable vapour was drawn into the inlet system and to prevent any flames from the exhaust system escaping into the air of the workplace. The engine and exhaust system should be designed to ensure that their surface temperatures were below the ignition temperature of the flammable substance and the fitting of a water jacket on the exhaust system together with thermal sensors and air cooling for ‘hot spots’ would provide additional protection. Electrical equipment on the engine should be suitable for zones 1 and 2, mechanical alternatives, as for example the fuel gauge, should be fitted where possible and electrical starters wired to a plug and socket in a safe area. The use of electrically conducting materials for parts such as tyres and drive belts would reduce static build up, while fitting speed limiters would help prevent over speeding or over loading of the engine. Finally it would be advisable to fit an air inlet shut-off valve to stop the engine if at any time vapour ingestion does lead to overspeeding. Answers to this part of the question were not to the same standard as part (a).
7
EXTERNAL
Section B – three from five questions to be attempted Question 7
For a large supermarket with restaurant facilities: (a)
(b)
outline the automatic fire protection systems that should be in place;
(6)
outline the factors to be considered when developing a safe means of escape for the supermarket.
(14)
For part (a), candidates were expected to outline automatic fire protection systems such as those for fire detection for example fire and smoke detectors; fire suppression systems such as automatic sprinkler systems or foam flooding systems which would need to be subjected to regular testing; a fire alarm system with adequate call points located at strategic points in the store and regularly tested before the store is opened to the public; a smoke control system comprising roof vents and automatic self closing doors; and an automatic fire service call out. Candidates should also have indicated which of these systems were more suitable for the supermarket and which for the restaurant. This was a popular question and part (a) was well answered though a few candidates seemed to miss the reference to ‘automatic’ and concentrated on manual means such fire extinguishers and hose reels. Factors which would need to be considered in developing a safe means of escape for the supermarket include the possible types and numbers of persons to be evacuated, the distance to fire escape routes and the number of routes available; the arrangements for evacuating members of the public which would include the use of the public address system and the appointment of fire marshals who would need training in their responsibilities including ensuring that all areas have been cleared; ensuring that fire exit routes are kept free from obstruction and are clearly signed with the routes from the supermarket and restaurant being sufficiently separated to avoid crowding and confusion; the location of clearly marked assembly points which should be in a safe position away from the building and positioned where they would not obstruct access for the emergency services; the provision of emergency lighting in the event of failure of the main supply; arrangements for liaison with the emergency services; the allocation of clear responsibilities to workers for giving assistance to customers and particularly those who might be disabled; arrangements for the disabling of lifts and for locking the tills to prevent the opportunities for theft; and the completion of regular fire drills at least at six monthly periods. Answers to this part of the question were reasonable but perhaps not as good as those provided for part (a). Only the better answers differentiated between the store and the restaurant. Others described the need for the building to be constructed of fire resisting material rather than the means to be provided to ensure people were able to leave it safely if a fire did occur.
8
EXTERNAL
Question 8
An external lift on a construction site has an interlocked guard to prevent the lift operating when the gate is open. With reference to the diagram: (a)
identify the two types of switch shown (Switch A AND Switch B);
(2)
(b)
identify the functional components associated with BOTH switches;
(4)
outline the normal sequence of operation for the electricallyoperated, cam-activated switch assembly when the gate opens and closes;
(6)
outline ways in which electrically-operated, cam-activated switches may fail to operate as intended.
(8)
(c)
(d)
For the first part of the question candidates were expected to identify that limit switch A is wired normally closed and is a positively operated switch while switch B is wired normally open and is negatively operated. In answer to part (b) they should have identified that the functional components of the switches are the cam follower or plunger, an internal spring compressed from the bottom, internal electrical contacts attached to the cam follower with the gate acting as the cam. In answer to part (c), a good answer would have outlined that when the gate is closed the normal sequence of operations would be the depression of the plunger on switch B and the compression of the internal spring and the release of the cam follower on switch A causing de-compression of the spring. This would allow electrical contact to be made in both switches, so making the circuit and allowing the operation of the lift. When the gate is open, the cam follower on switch A is depressed and the internal spring compresses while the cam follower in switch B is released causing decompression of the spring. The electrical contact is broken in both switches thus breaking the circuit and preventing the operation of the lift.
9
EXTERNAL
For part (d), there are a number of ways in which the type of switch described in the scenario might fail to operate as intended. These include failure of or damage to the internal spring which prevents the appropriate contact being made; damage to other internal parts of the switch; the presence of debris or dirt within the body of the switch; a contact weld through electrical arcing; a misalignment between cam and cam follower or a wiring fault; wear of or damage to parts such as a bent plunger; damage due to a corrosive atmosphere and sabotage such as deliberate disconnection of wiring or the ‘taping up’ of parts to simulate activation by the gate. This was not a popular question with very few making any attempt to answer it, and of those who did, many were confused between a normally closed and normally open cam operated switch or how the switches might fail to operate as intended.
Question 9
A small company manufactures products using electro-chemical processes. The company has poor general standards of health and safety, made worse by the presence of conductive and corrosive fluids and humid, corrosive atmospheres. (a)
(b)
Describe the types of fault that may be found under such conditions in a fixed electrical system.
(10)
Outline the technical information a competent electrician would require before conducting an inspection of a fixed electrical system.
(10)
The first part of this question sought to assess candidates’ knowledge of typical faults within a fixed electrical system and how a corrosive atmosphere may exacerbate the problems. Issues that should have been mentioned included poor earthing and a lack of earth continuity, damaged sockets and switchgear, covers missing from junction boxes, inadequate excess current protection such as the fitting of fuses with incorrect ratings, means of isolation in poor condition and badly sited and incompetent workmanship in the original installation. Additional problems caused by the atmosphere include exposed live conductors due to damaged or perished insulation, short circuits caused by the ingress of fluids, corrosion of system parts such as access grilles and transformer casings, and the unsuitability of the equipment for use in such wet and corrosive conditions. For part (b), the type of information required by a competent electrician prior to carrying out a survey would include: an inventory of the equipment with details of its type and manufacturer; the operating parameters of the system such as its voltage, current, number of phases and its impedance and/or resistance; its IP classification including the measure of protection against the ingress of water; any circuit diagrams and/or manuals for the equipment with details of any modifications made; means of isolation and its location; earthing arrangements; the type and size of cables; details on the operation of protective devices and copies of previous inspection reports. Answers to this question were to an acceptable standard with most candidates able to identify a range of faults that might be found. For part (a), some tried to explain the chemical reactions involved which was not required, and suggested the presence of a flammable atmosphere which was irrelevant. In their answers to the second part of the question, some candidates outlined the precautions to be taken rather than the information that the competent electrician would require.
10
EXTERNAL
Question 10
The International Labour Organisation’s Standard R175 and its associated Code of Practice sets out general principles for ‘Safety and Health in Construction’. Minor repairs need to be carried out to the sloping roof of a large twostorey property. A scaffold is to be erected in order to gain access to the work area. Using the guidance in R175, outline the precautions necessary for carrying out the repairs.
(20)
The more successful candidates were those who organised their answers under the general headings of scaffolds, ladder access, roof edge protection and general workplace precautions. For scaffolds, necessary precautions include ensuring that it is constructed of suitable and sound material, is of adequate size and strength and is erected and modified where necessary only by competent workers in accordance with any local regulations. The scaffold should be stable which may mean that it has to be tied in to the building. The working platforms must be provided with guard rails and toe boards to prevent the fall of persons and materials and means should be provided to restrict access when it is not in use. It is imperative that the scaffold is inspected prior to it being used for the first time, at regular intervals thereafter, after alterations or interruption in its use and after exposure to extreme weather conditions. Where ladders are used for access, they should be secured and extend for a distance of at least one metre above the landing platform. Workers using the ladder should always ensure three points of contact whilst climbing and arrangements should be made for lifting tools and materials to the working area by means of a hoist or gin wheel. Properly secured roof ladders should be used for work on a sloping roof with protection provided round those areas where fragile material may be present. Guard rails should be provided to protect workers from falling from eaves or roof edges. If it is not practicable to provide guard rails, and workers could fall a distance of more than 2 metres, then other means such as harnesses or nets must be used. General workplace precautions include those to be taken when work is carried out near to overhead power lines; the provision of chutes for the removal of debris or rubbish; the issue and wearing of personal protective equipment such as hard hats, boots, eye protection, gloves and high visibility clothing; and the provision of adequate welfare facilities. This was a popular question though Examiners suspected that there were many candidates who had limited knowledge of R175 given the content of their answers. Some related to UK standards and even the Work at Height Regulations whilst others misread the question and wrote of hazards rather than precautions.
11
EXTERNAL
Question 11
Outline the factors to consider with respect to the design, construction and use of a storeroom that is to be used for the storage of bulk stocks of palletised containers of highly flammable paints and thinners.
(20)
As far as the design and construction of the storeroom were concerned, marks were awarded for outlining factors such as the provision of adequate separation from occupied buildings and site boundaries and segregation from traffic routes with the use of fire walls if separation was not possible; the construction of the store on an impermeable base with fire resistant materials with a light weight roof or blast panels; the provision of high/low ventilation; the provision of bunding to retain any spilled liquid; ensuring that electrical installations were suitable for a zoned area; the provision of fire/smoke detection systems and of sprinklers and/or fire extinguishers; ensuring adequate spacing between racking to allow the movement of fork lift trucks and the provision of separate access for pedestrians and the trucks. Use of the storeroom would involve the control of ignition sources such as the fork lift trucks and portable electric equipment; the storing of paints and thinners in fire resistant containers away from sources of heat and sunlight; procedures for decanting which should be carried out outdoors or in a separate area; procedures for spillages where immediate cleaning up would be required using spill kits; ensuring a high standard of housekeeping for the fork lift truck routes and pedestrian walkways; introducing procedures for the regular inspection and maintenance of the racking and pallets; arranging for the safe disposal of waste; providing information and training to the workers on the necessary precautionary measures to be taken and controlling access to the stores by limiting it to authorised personnel only. This was a popular question, but few candidates were able to provide comprehensive answers. When referring to design and construction, the use of fire resistant materials and the provision of bunding and ventilation were most commonly mentioned but answers concerning the use of the building were limited with some apparently either not noticing or ignoring the presence of the word ‘use’ in the question and considering what precautions to be taken when work was to be carried out in a potentially highly flammable atmosphere. Some candidates inappropriately concentrated on the possible health effects of using solvent based paints and thinners.
12
EXTERNAL
The National Examination Board in Occupational Safety and Health Dominus Way Meridian Business Park Leicester LE19 1QW telephone +44 (0)116 2634700 fax +44 (0)116 2824000 email
[email protected] www.nebosh.org.uk
