NEBOSH International General Certificate
Paper II Workplace hazards and Control Question and Answers
1. (a) Identify FOUR sources of ignition that may lead to a fire in the workplace. (4)
(b) Outline methods of reducing the risk of a fire in the workplace. (8)
(c) Outline the measures that should be in place for a successful evacuation of a workplace in the event of a fire. (8)
Answer (a)
The main sources of ignition which lead to fire such as incorrectly installed electrical equipment; machinery and plant which was badly maintained such as friction caused by inadequate lubrication; chemical reactions that may give off heat; hot work such as welding or cutting; smoking materials which are discarded in an unsafe manner; hot surfaces such as those on cooking or heating appliances; sparks from cold working such as grinding; and static electricity arising from the incorrect transfer of flammable liquids.
(b) The ways of reducing the risk of a fire starting in a workplace include the control of smoking and smoking materials; good housekeeping to prevent the accumulation of waste paper and other combustible materials; regular lubrication of machinery to prevent sparks; regular inspection of electrical equipment for damage; ensuring that electrical systems are not overloaded and isolating equipment that is not in use; ensuring ventilation outlets on equipment are not obstructed; controlling hot work by permits or by the creation of designated areas; providing proper storage facilities for flammable liquids away from sources of ignition; segregating incompatible chemicals and implementing security procedures to reduce the risk of arson.
(c) The measures include: the provision of means for detecting the fire and for raising the alarm; an acceptable distance to the nearest available exit; escape routes of sufficient width and fire protected; clear signing of escape routes; the provision of emergency lighting; escape routes kept clear of obstructions with fire doors closed to prevent the spread of smoke; the provision of fire fighting equipment; the appointment and use of fire marshals; procedures for the evacuation of those with a physical impairment (in relation to hearing, sight or mobility); the identification of a safe assembly point and the need to practice the evacuation plan at regular intervals.
2 (a) Identify FOUR mechanical hazards associated with the use of a pedestal drill.(4)
(b) Outline FOUR control measures to reduce the risk of injury to operators of pedestal drills. (4)
Answer
(a) Mechanical hazards associated with the use of a pedestal drill include: entanglement of clothes or hair with the drill bit or chuck; stabbing injuries from the end of the drill bit; contact with the drill chuck resulting in abrasions; and ejection of, or impact by, unclamped work pieces, made worse by the fact that the work piece may be spinning at fast speed on the bit. Cutting hazards may also be presented by metal swarf produced by the drilling process.
(b) Control measures which could reduce the risk of injury to operators include ensuring stop/start controls, emergency stop devices and isolator switches are operative; the fitting of robust and adjustable guarding around the chuck and drill bit; ensuring the regular removal of swart round the drill bit to prevent build up; the removal of the chuck key before putting the drill into motion; ensuring the operators are trained and competent and are not wearing items of loose clothing and/or jewellery; the provision of personal protective equipment such as eye and face protection and introducing procedures for the regular maintenance of the machine.
3. Identify the main hazards associated with demolition work. (8)
The main hazards associated with this type of work include working at height; falling debris and premature collapse; use of explosives; contact with and noise from equipment and heavy plant; the presence of dust which might possibly include asbestos; the presence of flammable substances or hazardous materials from previous uses of the building; the presence of cellars or vaults affecting the stability of adjoining premises; the possible presence of services such as electricity, gas and water; biological hazards arising from the presence of vermin and stagnant water; the presence of sharps such as nails and glass and hazards arising during manual handling operations.
4. A recent increase in work-related ill-health has been noticed amongst workers who use a solvent for which a workplace exposure limit (WEL) has been set.
a. Explain the meaning of the term 'workplace exposure limit'. (2)
b. Give possible reasons for the increase in work-related ill-health amongst the workers. (6)
Answer
(a) The term "workplace exposure limit" (WEL) is concerned with concentrations of hazardous substances in the air that people breathe averaged over a specified period of time and referred to as a time-weighted average. Two time periods are used: long-term (8 hours) intended to control effects by restricting the total intake by inhalation over one work shift and short-term (usually 15 minutes) to control effects that may be seen after a brief exposure.
(b) Important reason for the increase in work-related ill-health might have been the inadequacy of the original risk assessment carried out for the operation or a subsequent increase in the frequency and duration of the exposure of employees
Additionally, the original degreasing solvent might have been replaced by a new solvent for which no risk assessment had been carried out. Other reasons would include a failure to carry out health screening of new employees or to give them adequate training on the precautions to be observed; an increase in the quantity or concentration of the solvent used; an inadequate or poorly maintained local exhaust ventilation system; a failure to carry out regular monitoring to ensure the work exposure limit was not being exceeded and a poor standard of personal hygiene on the part of the workers.
5. Repair work is to be carried out on the roof of a school.
(a) Identify control measures to reduce the risks to roof workers. (6)
(b) Identify TWO control measures to reduce the risks to other persons. (2)
Answer
(a) The work activity and initially an assessment should be made to gauge the condition of the roof and to check for the presence of fragile materials. It would then be necessary to provide safe means of access, normally by the erection of a scaffold; to use roof ladders or crawling boards; to erect edge protection with guard rails and toe boards to prevent the fall of persons and materials and either to provide barriers and signage round areas on the roof containing fragile materials or to cover them to prevent persons falling through. Other precautions would include provision for transporting tools and materials to the roof and the removal of waste; the use of appropriate personal protective equipment such as hard hats and footwear and the employment of competent personnel. (b) Control measures that would reduce the risks to others include the provision of barriers at ground level to prevent access to the working area by children, teachers or members of the public; scheduling the work so that the more hazardous operations are carried out when the school was unoccupied; the prevention of unauthorized access to the roof by removing or blocking off ladders; introducing a high standard of monitoring and supervision and paying a good will visit to the school to advise on the potential hazards associated with the operation and the precautions that should be taken by staff and pupils.
6. Outline prevention strategies an organization could consider to reduce the risk of violence towards workers. (8)
Answer
The prevention strategies include, the completion of initial risk assessments by a competent person; the design of the workplace and public areas to restrict access and the use of security equipment such as CCTV, alarm systems and personal alarms and panic buttons; secure areas with coded locks and physical barriers and the use of check-in and check-out procedures; job design with a reduction in cash holdings and the introduction of by appointment systems and team working where practicable; the use of trained security staff; procedures for lone and out of hours working and for home and off-site visits; introducing procedures for the reporting of incidents and providing employees with training in confrontation management and stress reduction techniques.
7. Workers are employed to carry out ground maintenance on a large area of land containing grass, bushes and trees. Outline the hazards to which they may be exposed. (8)
Answer:
Hazards such as those connected with the use of tractor units, mowing machines and hand held strummers including the possible exposure to noise and vibration; those involved with the manual handling of machinery and refuse; slips, trips and falls including falls from a height when carrying out tree surgery; hazards associated with the handling of fuel, pesticides and other chemicals; the possibility of being bitten by animals and/or insects or coming into contact with animal faeces or discarded drugs paraphernalia; and hazards involving prolonged exposure to the sun or conversely to adverse weather conditions.
8 (a) Identify FOUR forms of a hazardous substance for which respiratory protective equipment could be used to reduce the risk of harm. (4)
(b) Outline factors that could reduce the effectiveness of the respiratory protective equipment. (4)
Answer
(a) The forms of hazardous substances such as dusts, gases, vapours, mists, fume and micro-organisms (b) The factors include a reduction in battery power; the fitting of incorrect cartridges or a failure to replace them before saturation; equipment incorrectly fitted, perhaps due to facial characteristics, or incompatibility with other personal protective equipment being worn; the level of the hazard and the work rate of the individual; inadequate training in its use; poor maintenance and inadequate facilities for storage; damage occurring during use and a failure to provide the level of monitoring and supervision to ensure the equipment was always used when required.
9 (a) Identify the effects on the human body from a severe electric shock. (4)
(b) Identify FOUR factors that could affect the severity of injury resulting from contact with electricity. (4) Answer
(a) The effects include the interference with nervel muscle action, leading to involuntary grip; cardiopulmonary effects, in particular, the risk of fatal injury due to disruption of heart rhythm; and tissue burns - but should have added to this by referring to the main sites of damage as being the entry and exit points and to the possibility of damage to internal organs. (b) The factors such as the voltage and the type and size of the current involved; the path taken through the body by the current; the length of contact time; the general health and age of the person involved; the electrical resistance of the skin and the internal body resistance; factors associated with the footwear and clothing being worn by the person; environmental issues such as the floor surface and the possibility of secondary sources of injury particularly if the person affected is working at a height.
10 A worker is manually loading boxes of components onto metal shelves.
(a) Identify FOUR types of injury that the worker could suffer while carrying out this task. (4)
(b) Identify factors in relation to the task that will increase the risk of injury. (4)
(c) The identifying potential injuries such as spinal disc compression or a prolapsed disc; strains to tendons, muscles or ligaments; a hernia; dislocation or fracture of bones; cuts and abrasions; crushing or impact injuries and work-related upper limb disorders (WRULDs).
Answer (a) The four types of injuries include spinal disc compression or a prolapsed disc; strains to tendons, muscles or ligaments; a hernia; dislocation or fracture of bones; cuts and abrasions; crushing or impact injuries and work-related upper limb disorders (WRULDs). (b) The identification of factors related to the task which could have increased the risk of injury. Examiners were looking for the identification of task-related factors such as the manipulation of the load at a distance from the trunk; the work rate and periods allowed for rest and recovery; excessive carrying distances; excessive lifting or lowering distances; and the need to adopt unsatisfactory body positions because of space restrictions.
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