UNIT IGC2 CONTROL OF INTERNATIONAL WORKPLACE HAZARDS
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IGC2: CONTROL OF INTERNATIONAL WORKPLACE HAZARDS EXAMPLE LONG QUESTIONS Question 1 Battery-powered forklift trucks are used in a warehouse to move pallets around. (a) Describe FOUR hazards arising from the use of battery-powered forklift trucks. (4) (b) Outline the controls needed to ensure pedestrian safety in locations where the forklift trucks are in use. (8) (c) Outline EIGHT rules that must be adhered to when a forklift truck is left unattended by the driver during a work shift. (8) Model Answer (a) There are a number of hazards associated with battery-powered forklift trucks. The main hazards relate to charging the battery of the forklift truck. They include the generation of hydrogen gas (which is highly explosive) and the potential release of battery acid. For this reason battery charging should be completed in a designated area that is well ventilated. This will prevent any build-up of fumes which could in turn lead to explosion and/or injury to personnel. There are also hazards associated with the handling of the batteries including manual handling and contact with battery acids. Contact with electrical components is another hazard that could result in electric shocks or burns. Collision with pedestrians might occur due to the near silent running of the truck. (b) In order to ensure that pedestrians are kept safe in areas where forklift trucks are being used, there are a number of precautions that must be implemented. Firstly, it is important to have traffic routes marked out so that it is clear where forklift trucks are allowed. In addition, pedestrian routes should be clearly marked and forklift trucks must not be allowed in pedestrian areas. Where possible, pedestrian areas should be physically segregated from the traffic route the warehouse should have adequate lighting to ensure good visibility at all times. Fixed wall mirrors may also be necessary for use on corners. In addition, high visibility clothing and transparent doors will ensure that personnel can be seen easily at all times. The forklift trucks must be fitted with audible alarms and, in particularly noisy environments, rotating or flashing lights may also be necessary. It is also important to ensure that safe systems of work for loading, unloading and stacking are in use and are being adhered to at all times. In the same way, it is essential that all rules relating to the safe use of the forklift trucks are enforced, particularly those relating to speed restrictions and access. In addition to the above, it is vital that drivers and pedestrians are adequately trained and supervised to ensure that the precautions above are adhered to. (c) There are a number of rules that a driver must follow when leaving his/her forklift truck unattended. The first one relates to leaving the forklift truck on a firm level surface, in a designated area, to ensure that it cannot roll away. The truck must not be left in a position where it could obstruct emergency exits, walkways or fire points, and must be parked away from other vehicles. The truck should be left with the mast tilted slightly forward and forks resting on the floor to make sure that it is stable and not likely to overturn. The truck must not be left until the brake has been applied and the power switched off. Where a start key is used, the key must be removed and returned to a responsible person, as appropriate. This will prevent unauthorized use of the truck.
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Question 2 New owners are about to move into an existing office building. (a) The new owners are carrying out an assessment of the suitability of lighting within the building. Identify the factors that should be considered. (8) (b) Outline FOUR factors, other than lighting, associated with the physical working environment that may impact on the health and safety of personnel. (4) (c) Outline the welfare facilities required in the building. (8) Model Answer (a) When assessing the suitability of lighting within the building, the new owners must consider a number of factors. Firstly, they must consider the tasks to be undertaken and the equipment to be used. Where close work is to be carried out, then the lighting requirements will be greater than where general office administration is being completed. Again, where intricate machinery requiring precise setting is being used, then extra localized lighting may be required. The new owners must look at the suitability of the existing lighting in all areas including stairs and corridors. They must also look at the amount of natural light in the building and make best use of this, as natural light is preferable to artificial light. In addition, they must also consider significant contrast in lighting between different areas. For this, they must look at the layout of the office including the positioning of screen dividers in relation to overhead lighting, and other areas that may be in shadow. It may be possible to move screens and/or furniture around to improve existing lighting levels, or to reduce/remove glare from computer screens. The condition and appropriateness of the artificial lighting must be considered. Flickering fluorescent tubes can be annoying, as can excessive glare caused by spotlights in the wrong place. The maintenance and the cleaning procedures may also require consideration. Emergency lighting must also be considered, as people are especially exposed to danger in the event of a lighting failure. (b) The physical working environment can be affected by a great many factors which can affect the health and safety of the employees working in that environment. One such factor is noise, which can have a stressful effect on employees. Another factor is temperature. Extremes of temperature can affect an individual’s ability to concentrate and can make them feel physically unwell. For an office environment, a temperature of 16 degrees Celsius is reasonable. Space constraints may also affect employee health and safety. Cramped conditions may make individuals feel claustrophobic. Additionally, though, inadequate space may result in accidents. Ventilation is another important factor. Enclosed workplaces must be ventilated by a sufficient quantity of fresh or purified air. Poor ventilation may make employees feel ill with symptoms such as headaches and nausea (Sick Building Syndrome). (c) There are a number of welfare facilities that are required in the building. An adequate number of well-ventilated and well-lit sanitary conveniences in relation to the number of male and female employees are essential. In addition, washing facilities with hot and cold running water and a means of drying must be available. A source of drinking water must be present, and this must be clearly marked, where appropriate. There must also be some facilities for taking rest and refreshment away from the working area. Additionally pregnant women and nursing mothers must have rest facilities. The building must protect nonsmokers from the effects of inhaling tobacco smoke. Many buildings will have a designated area for smoking or smokers may be obliged to go outside. Accommodation must be available for clothing not worn during working hours, e.g. coats, etc. This accommodation may take the form of lockers or merely a hook. First-aid facilities must be available. The number of people employed in the building will determine whether a first-aid kit is adequate, or whether a fully equipped first-aid room is required. Page 3 of 32
EXAMPLE SHORT QUESTIONS Question 1 Outline the principal health effects of the following agents and, for EACH ONE, identify the work situation in which a person may be exposed: (a) Carbon monoxide. (2) (b) Asbestos. (2) (c) Legionella bacteria. (2) (d) Hepatitis virus. (2) Model Answer (a) The principal health effects of carbon monoxide are headaches, drowsiness and possible suffocation. Exposure could occur when working near a vehicle exhaust in an unventilated area, e.g. vehicle repair premises. (b) Exposure to asbestos may cause asbestosis (a fibrotic disease of the lung), lung cancer or mesothelioma (cancer of the lining of the lung). Workers engaged in maintenance or demolition work where asbestos is contained in the fabric of the building are at risk. (c) Exposure to Legionella bacteria may cause legionellosis, which is characterised by flulike symptoms, pneumonia and in about 15% of cases, death. Any workplace that has untreated water tanks and systems from which water droplets may be released into the atmosphere (e.g. from air-conditioning systems or cooling towers) poses a risk to those in the vicinity. (d) The principal health effects of the hepatitis virus include jaundice, fever, abdominal pain and, ultimately, liver failure. Any workplace situation that exposes people to infected persons or used hypodermic needles presents a risk, e.g. hospitals. The Hepatitis A virus, which is normally less serious, is transmitted via the mouth; Hepatitis B and C via the blood.
Question 2 Outline the requirements necessary to evacuate people safely from a building on fire. (8) Model Answer In order to ensure the safe evacuation of people from a building, it is important that the following requirements are in place. Firstly, there must be a means for raising the alarm (e.g. fire alarm, hand bell), and the distance to the nearest available exit must be acceptable. Escape routes must be of sufficient width and have clear signage to indicate the escape route. In addition, escape routes must be kept clear of obstructions, with fire doors closed to prevent the spread of smoke. Appropriate fire-fighting equipment must be provided and be in full working order. Emergency lighting must be provided where necessary. In order to ensure that the evacuation process itself runs smoothly, fire marshals must be appointed. These marshals will ensure that the building is evacuated fully and that nobody is left inside. There must also be procedures to evacuate people with a physical disability, e.g. in relation to hearing, sight or mobility. It is important to practice the evacuation plan at regular intervals. Page 4 of 32
Question 3 (a) Consider a piece of machinery with moving parts and identify: (i) TWO mechanical hazards (associated with the moving parts). (2) (ii) TWO non-mechanical hazards that the operator of the machine may be exposed to. (2) (b) In order to reduce the risk of injury from dangerous parts of the machinery, outline a hierarchy of control measures that may be used.(4) Model Answer (a) (i) Mechanical hazards are those from the moving parts of the machinery and/or the material being worked and include impact and entanglement. (ii) Non-mechanical hazards that could affect the machine operator include noise and vibration. (b) A hierarchy of control measures that could be used to reduce the risk of injury from the dangerous parts of the machine commences with the fitting of fixed guard(s). These enclose the dangerous parts and must be fixed in place. Where fixed guards are not practical, then other types of guards, e.g. interlock guards (where the machine cannot start before the guard is closed), or protective devices, e.g. trip systems or pressure sensitive mats, should be considered. Where guards cannot give full protection, safety aids such as jigs, push sticks or holders can be used. In addition to the above, the provision of information, training and supervision are important to ensure that operators use the machines safely. Question 4 Consider an individual lifting a load. Outline the factors that may affect the risk from manual handling in relation to: (a) The load. (4) (b) The individual. (4) Model Answer (a) The nature of the load may present a risk of injury during manual handling activities. Important factors to consider are the size and the weight of the load. In addition, consideration should be given to whether the contents of the load may move and the load become unbalanced. The position of the centre of gravity is important too. If the centre of gravity is not in the centre then this can make the manual handling activity more difficult. Consideration must also be given as to how easy it is to secure a firm grasp of the load and whether sharp edges are present. (b) The individual carrying out the task may affect the level of risk of a manual handling activity. Firstly, one should consider the body size and strength of the individual in relation to the task. The age and gender of the individual must also be considered. Other factors such as physical handicaps or restrictions due to illness, disability or pregnancy should be taken into account. Note that individual lack of training in manual handling will increase the level of risk associated with the task. Finally, inappropriate clothing or footwear will also increase the level of risk associated with the manual handling activity.
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ELEMENT 1: MOVEMENT OF PEOPLE AND VEHICLES – HAZARDS AND CONTROL Short Questions 1. State the primary hazards associated with the movement of people and vehicles. (8 marks) The primary hazards associated with the movement of people and vehicles are: Slips, trips and falls on the same level and from height Collision with moving vehicles Collision with or being struck by a falling object, e.g. part of a load Striking against fixed or stationary objects Environmental conditions 2. Outline the precautions that might be needed to ensure the safety of pedestrians in areas where vehicles are in use. (8 marks) To ensure the safety of pedestrians and vehicles and to prevent them coming into contact with each other, the following precautions should be used: Segregation of pedestrians and vehicles Separate pedestrian and vehicle routes Speed limits for vehicles Signage; audio and/or visual alarms Road marking Training of drivers Guarding and barriers Maintenance of floor and traffic routes Employee awareness 3. Identify FOUR factors to consider when selecting potential drivers for workplace transport and equipment. (8 marks) When selecting potential drivers for workplace transport and equipment, the following factors should be taken into consideration: Competence Training in use of any special features or requirements Age – generally at least 17 years old Reliable Able to perform task in a responsible manner Reasonable fitness Reasonable intelligence (Only four factors are required.)
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4. State FOUR reasons why a forklift truck may overturn in the workplace. (8 marks) A forklift truck may overturn due to: Loss of control Speed of travel Steepness of a slope Travelling with a raised load Uneven tire pressure Poorly-maintained road surfaces Environmental conditions Wind 5. Outline the means by which the risk of accidents from reversing vehicles within a workplace can be reduced. (8 marks) Accidents from reversing vehicles can be reduced by: Avoiding the need for vehicles to reverse – one-way or drive through systems, turning circles, etc. Separation of vehicles and pedestrians – use of barriers and signs Suitable vehicle and workplace design – audible alarms, mirrors on vehicles and at blind corners, refuges, adequate lighting, etc. Procedural measures – use of banks men, good site rules, driver training, etc 6. A high percentage of the many fatal accidents which occur every year are caused by workers being struck by vehicles. Outline the necessary precautions to reduce risks of vehicle accidents. (20) The precautions which can be used to reduce the risk of vehicle accidents will include the following: Road systems clearly lit and one-way traffic clearly marked. Space for parking, reversing, loading and unloading Use of crossings and white and yellow lines Vehicles not allowed to reverse unless necessary and then only with a banks man and controls, like alarms. Avoiding sharp bends Protection of vulnerable plant Barriers Segregation of pedestrians and vehicles Parking areas Maintenance of roadways Speed limits and restrictors Signage 7. Diesel powered fork lift trucks are used in wide range of organisation and can introduce additional hazards into the working environment 1. Identify four hazards associated with such vehicles that may pose a risk to the health of drivers. 2. Describe the various circumstances that may cause such a vehicle to overturn Page 7 of 32
3. Outline the precaution may be needed to ensure the safety of pedestrians in areas where fork lift trucks are operating 1. Hazards particularly relevant to drivers such as: Fumes Fire and explosion Collision with buildings Manual handling Falling object Noise Vibration Ergonomics 2. A forklift truck may overturn due to: Loss of control Speed of travel Steepness of a slope Travelling with a raised load Uneven tire pressure Poorly-maintained road surfaces Environmental conditions Wind 3. Segregation of pedestrians and vehicles Separate pedestrian and vehicle routes Speed limits for vehicles Signage; audio and/or visual alarms Road marking Training of drivers Guarding and barriers Maintenance of floor and traffic routes Employee awareness 8. Outline the hazards and corresponding precautions to be taken when charging batteries for fork lift trucks. Hazards of battery charging Release of hydrogen gas during charging (fire and explosion) Electrical short circuits Corrosive and burning effect of battery acid Manual handling of batteries, etc Precaution for charging batteries should be: Well ventilated area to prevent build up of hydrogen No sources of ignition near refuelling/recharging points Suitable PPE (acid resistant gloves, eye protection etc.) Insulated tools / procedures for connecting charger. Lifting equipment for removing batteries. Page 8 of 32
9. Outline the factors that should be taken into account when planning traffic routes for internal transport When organising traffic routes the precaution should be: Keep pedestrians and vehicles apart Separate routes, designated crossing places and suitable barriers at recognised danger spots. High visibility clothing if necessary Clearly marked and signed traffic routes Roads, gangways and aisles should have sufficient width and overhead clearances for the largest vehicle Speed limits are established and enforced Adequate lighting should be provided Good all round visibility Clear direction signs and marking of doors Sharp/blind bends and overhead obstructions should be avoided The floor surface should be in god condition Any gradient should be kept as gently as possible Sufficient and suitable parking areas should be provided Avoid reversing if possible Making people aware of the moving of vehicles 10. List the ways in which a dumper truck may overturn Overloading or uneven loading of the bucket Cornering at excessive speed Hitting obstructions Driving too close to the edges of embankments or excavations Mechanical defects Inappropriate tyre pressure Driving across slopes. 11. List items to be included on a checklist for the routine inspection of a fork lift truck at the beginning of a shift Condition and pressure of tyres Functioning of lights, horns, brakes Warning devices working Suitable mirrors Engine for oil leaks Water leaks Seat securely fixed and suitable restraints where fitted Signs of damage to bodywork and lifting mechanism Security of equipment fitted i.e. LPG tank 12. Outlines how slip and trip hazards in the workplace might be controlled The precautions that should be taken to prevent slips and trips should include Designated walking routes where possible Ensure walkways are level Ensure walkways are non slip Page 9 of 32
Well lit and clearly marked walkways Procedures to quickly identify and remove spillages and obstacles Eliminate need to carry loads Make employees aware of the hazards 13. List 8 design features or safe practices intended to reduce the risk of accidents on staircase used as internal pedestrian routes within work premises. Adequate width The provision of handrails The dimension of treads and risers The provision of landings Special provisions for disabled persons Possibility of using a lift as an alternative Avoid the need to carry large or heavy items up or down stairs. Appropriate footwear – low heels The provision of non-slip surfaces together with reflective edging. The adequate lighting and effective maintenance The removal of obstructions, with particular attention to escape route 14. Outline the factors to consider when assessing the risk to a long distance delivery driver. The job Duration of journey Road condition Means of communication Security The driver Physical and psychological capabilities The level of training The vehicle Suitability for the load Design and layout of cab Vehicle maintenance The load Properly labelled if hazardous Spillage procedures if hazardous Weight Value
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15. Outline the precaution that should be considered when parking a fork lift The precautions when parking fork lift trucks should include: Designated parking area Applying brakes Controls in neutral position Switch off engine Removing key and returning to responsible person Forks resting on floor Mast tilted slightly forward Not obstructing walk ways Not obstructing fire exits / fire points
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ELEMENT 2: MANUAL AND MECHANICAL HANDLING HAZARDS AND CONTROL Short Questions 1. Identify FOUR specific types of injury that could be caused by manual handling of loads. (8 marks) Specific types of injury caused by incorrect manual handling of loads are: Back injuries Muscle strains and sprains Hernias Cuts, abrasions and bruises Bone injuries, particularly to toes and fingers WRULDs Musculoskeletal disorders 2. Identify the FOUR main factors to consider when carrying out a manual handling assessment. Give an example for EACH. (8 marks) The four main factors to consider in a manual handling assessment are: The load, e.g. is it heavy The individual, e.g. does the load require unusual strength The task, e.g. how far is the load to be carried The environment, e.g. is the floor even 3. (a) Outline a good lifting technique that could be adopted by a person when lifting a load from the ground. (4 marks) The following are important to ensure a safe lifting technique: Stop and think Assess the weight of the load Bend the knees Keep the back straight Get a good grip on the load Use of body weight Keep the load close to the body Don’t twist the body Position the feet slightly apart Keep the shoulders and hips in line (same direction) Lift steadily using the leg muscles to straighten up (b) Give TWO examples of how a manual handling task could be avoided. (4 marks) FLTs Hoists Cranes Conveyors (Remember that the use of sack trucks and smaller loads does NOT avoid manual handling in the context of the question.) Page 12 of 32
4. When selecting a crane for a lifting operation, outline the steps to take in maintaining a safe system of work. (8 marks) Planning the lift Correct selection of crane Correct selection of lifting tackle Ensure the competence of the crane driver and slingers Ensure there is a valid and current test certificate
5. A store man is engaged in placing boxes of metal components by hand onto shelves. (i) List FOUR types of injury to which the store man may be at risk while carrying out the operation. (4 marks) Types of injury likely to be suffered: Back injuries and other muscular-skeletal disorders Muscular problems – strains and sprains Hernias Cuts, abrasions and bruising to hands and toes Bone injuries to hands and feet Work-related upper limb disorder (WRULDs) (ii) Outline the factors, in relation to the task, that will affect the risk of injury. (4 marks) Factors relating to THIS task are: Distance of the load from the body Movements that include twisting, stooping or reaching upwards Excessive lifting or lowering Sudden or jerking movements Excessive periods of physical effort Length of rest periods doing other types of work An imposed rate of doing work 6. (a) Identify the FOUR main factors to be considered when carrying out a manual handling assessment. (4 marks) The four main factors to consider in manual handling assessments are: The task The load The individual The working environment (b) Outline steps to reduce the risks from manual handling tasks and give an example in EACH case. (16 marks) The steps that should be taken to reduce the risks from manual handling tasks are as follows: Eliminate the need to carry out manual handling tasks, e.g. redesign the task to avoid manual handling altogether Page 13 of 32
If this is not possible, minimize the risk to as low as is reasonably practicable by using mechanical aids, e.g. a trolley to take the weight Give information, instruction and training to employees, e.g. training in correct lifting technique Look at environmental conditions, e.g. redesign the workstation to improve access to the load and any equipment used 7. With respect to manual handling operations a) Identify ways in which the nature of a load my present a risk of injury (4) b) State four factors relating to the individual that may increase the risk of injury (4) a) Load The factors to consider with the load should include Weight Size Shape Rigidity Outside surfaces Stability of contents Other hazards e.g. hot, cold, sharp etc. b) Individual Factors relating to individual should include: Sex Physical strength Stature State of health Level of training Person’s perception of their own ability 8. Outline four hazards and the corresponding control measures to be taken when using conveyor systems for moving materials within a workplace. Hazards of conveyors Trapping, limbs can be drawn into in-running nips Contact with moving parts, for example drive elements, screw conveyors Entanglement with roller, drive mechanisms Striking, materials falling from heights, incorrectly handled Impact, e.g. striking head Items falling off Slips, fall into rollers Manual handling Noise
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Hazards control measures Fixed guard on drums Side guards, enclosing conveyed items Trip wires, if necessary, along the full length of the conveyor Emergency stop buttons Safe access at regular intervals Avoid loose clothing Restrict access Wear head protection Regular maintenance by competent people 9. Outline the practical measures to avoid manual handling injuries The practical measure can include Avoid manual handling Risk reduction Automation and mechanisation Team handling Training Smaller lighter loads Selection Good environmental working conditions. 10. Outline the precaution when using 1. Hoist 2. Lifting accessories. Hoist Controls only operated from one position Clear visibility of landings Clear signals Secure objects being carried on goods hoist Do not overfill items being carried on goods lifts Do not carry loose items of goods lifts No passengers on goods lift Safe working load clearly marked Hoist properly examined and tested. Suitable fencing and gates at all levels Training in use of hoists Lifting accessories All accessories properly certificated and tested Properly inspected by a competent person at regular intervals Safe working load clearly marked Inspection prior to use No repair to accessories on site Not be used for purposes not intended Packing between accessory and load Properly stored after use Training provided for staff in safe use Page 15 of 32
11. Outline the precaution to be taken when using a mobile elevating work platform (MEWP) to reach a high point such as the streetlight Inspect the equipment before use and to ensure it is in good state of repair Using only competent workers Using outriggers and brakes Erecting warning signs and barriers to avoid collisions Ensuring the platform is not overloaded Wearing a harness
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ELEMENT 3: WORK EQUIPMENT HAZARDS AND CONTROL Short Questions 1. Outline the factors that would ensure piece of work equipment is suitable for use. (8 marks) To ensure that an item of work equipment is suitable for use, it must: Be capable of being maintained. Be provided with information and instructions for use. Have an appropriate control system with start, stop and emergency controls. In the EU it must meet requirements of EU standards and be CE marked. Have appropriate lighting. Have appropriate warning signs. Be stable. 2. Outline precautions for the safe use of hand-held tools. (8 marks) A control strategy for the safe use of hand-held tools consists of: Appropriate training Correct maintenance. Visual checks Appropriate PPE 3. Identify, using an example in EACH case, FOUR mechanical hazards associated with machinery. (8 marks) Mechanical hazards associated with machinery are: Crushing, e.g. trapping a finger between moving parts when opening a photocopier. Shearing, e.g. trapping a finger while using an office guillotine. Cutting or severing, e.g. coming into contact with the blade of a handsaw. Entanglement, e.g. a loose cuff getting caught in an abrasive wheel Drawing-in, e.g. a finger being drawn in while using a document shredder Impact, e.g. with a robot making unanticipated movements Stabbing or puncture, e.g. by a sewing machine needle Friction or abrasion, e.g. coming into contact with a sander 4. Outline FOUR non-mechanical hazards found in using machinery, and in EACH case give an example. (8 marks) Non-mechanical hazards associated with machinery are: Noise, e.g. from a cylinder mower, leading to temporary hearing loss Vibration, e.g. from a chainsaw, leading to vascular disorders Electricity, e.g. a faulty drill, causing electric shock or burns Temperature, e.g. burns from a cutting torch Radiation, e.g. from an X-ray machine, leading to the development of cancer Substances, e.g. inhaling sawdust from the working process Ergonomics, e.g. stress from the need to keep pace with a conveyor system Page 17 of 32
5. Outline FOUR guarding methods for machinery and, in EACH case give an example. (8 marks) The following are guarding methods for machinery: Fixed guard, e.g. to enclose a belt-drive mechanism Distance guard, e.g. a fixed perimeter fence round a machine Interlocking guard, e.g. to protect from the cutting operation of a lathe Trip device, e.g. a trip bar guard fitted to a pillar drill Adjustable guard, e.g. for the cutter on a milling machine Self-adjusting guard, e.g. on a metal-cutting saw Two-handed control, e.g. on a power press 6. A bench-mounted circular-saw is being used in a workshop to cut wood in the manufacture of wooden pallets. (a) Identify FOUR risks to the health of the saw operators. (4 marks) Risks to health would include: Hearing damage Hand-arm vibration Respiratory problems (e.g. asthma, nasal cancer, lung cancer) Dermatitis (b) Identify FOUR risks to the safety of the operators. (4 marks) Risks to safety (i.e. and resulting in injuries) would include: Injuries caused by entanglement on rotating parts such as the spindle of the blade and transmission (gear-driven parts). Flying particles of wood and ejection of wood (and any metal fragments of blade) causing injury. Manual handling injuries Electrocution or electrical burns Injuries due to slips, trips and falls (c) Outline FIVE non-mechanical hazards associated with machinery, and in EACH case describe how the associated risks can be minimized. (12 marks) The remedial measures and non-mechanical hazards would be: Completion of a risk assessment for the activity Provide an adjustable guard for the top of the saw; expose as little blade as possible. A fixed guard for the blade running below the bench Protection at the rear of the blade Availability of jigs and push-sticks to keep the operator’s hands away from the blade at the end of the cut Provision of emergency stop buttons; means of machine isolation Adequate space around the machine with the floor kept in sound condition – free from debris and loose material. Fitting and regular maintenance of properly designed LEV system Adequate level of lighting and heating Page 18 of 32
Provision of appropriate personal protective equipment such as goggles, ear defenders and gloves 7. Outline practical precautions to be taken prior to the maintenance of machinery. (8) The practical precautions when undertaking machinery maintenance could be: Isolate electrical power Permit-to-work system Isolation of any services or pipelines to the machine Allow hot machinery to cool Release loads Segregation by providing barriers and warning signs Provision of safe means of access, Provide adequate lighting, means of access, etc Ensuring availability and suitability of PPE Ventilate work area Adequate supervision Ensuring only skilled and competent staffs are used. 8. Identify the specific hazards associated with routine maintenance of machinery (4) Outline the hazards identified in (a) may be controlled (4) Whilst undertaking routine maintenance of machinery the hazards could be: Unintentional starting of machinery Release of stored energy e.g. pressure, electricity. Movements due to gravity Residual high or low pressure Restricted access/egress Residues e.g. chemicals, flammables, corrosives Mechanical hazards Heat or cold Biological hazards Confined spaces Working at height 9. Outline the issues that should be addressed in assessing the appropriateness and suitability of a guard to protect dangerous parts of a machine. Is compatible with the process, e.g. resistant to dust, chemical, etc.; Is of good construction Has adequate strength Is maintained in an efficient state Allows maintenance without removing the guard, e.g. by provision of lubrication / greasing points outside the guard Is situated a safe distance from the danger zone Does not increase the risk Does not restrict the operators view of the hazard Is not easy to bypass
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10. Identify four mechanical hazards presented by pedestal drill and in each case, how injury may occur (8) Entanglement (hair / clothing) Contact (stabbing / puncture), hand under drill Impact from an unsecured work piece Cutting from swarf Ejection of a broken bit or of materials 11. Outline a hierarchy of control measures that may be used to reduce the risk of injury from dangerous parts of machinery. (8) To select the appropriate guard the following hierarchy of measures should be considered: Fixed guard enclosing every dangerous part Other guards or protection devices (interlocks, etc) Protective appliances (jigs, holders, push sticks, etc.) The provision of information, instruction, training and supervision as is necessary in each case. 12. A public services worker uses a petrol-driven strimmer to maintain roadside grass verges. 1) Describe the possible hazards faced by the worker in carrying out this work (10) 2) List 5 items of PPE that should be provided to , and used by , the worker (5) 3) Outline measures other than the use of PPE (5) 1. Contact with the moving parts of the strimmer The possibility of being struck by flying stones or other material Slips/trips/falls Manual handling hazards The danger posed by moving traffic, noise, vibration, dust, and fumes The hazards associated with the storage and transfer of petrol. 2. Ear defenders Eye protection Respiratory protection (dust mask) Gloves Safety foot wear Gaiters High visibility clothing that also afforded protection against the weather 3. The use of traffic control or barriers The selection and maintenance of equipment to reduce to a minimum the levels of noise and vibration The provision of information, instruction, training and supervision, and health surveillance
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13. Identify advantages and disadvantages of a fixed machine guard (8) Advantages Fixed guards are at the top of hierarchy because they have no moving parts and are therefore very reliable and can be totally effective unless removed or damaged Fixed machined guard Require minimal maintenance because there are no moving parts Can only be defeated by a deliberate act Require only a visual inspection to check effectiveness May protect operators from other hazards, e.g. noise, dust, ejection of materials Limitations A fixed guard Is not linked to the machine controls Provides no protection when removed during maintenance (some maintenance work may require the machine to be run) Allows people to access dangerous parts while the machine is running once the guard has been removed Is more difficult to remove, therefore, not practical where frequent access is required for material feeding or for maintenance/adjustment/lubrication Tends to be left in an unfixed condition when frequent access is required due to machine problems May hamper visibility of the work being performed 14. Outline the factors that consider the safe operation of work equipment (8) To ensure the safe operation of work equipment number of factors may have to be considered The equipment should have appropriate protection against risk to employees from failure of or in work equipment. This includes the risk of ejection of parts or fire and explosion Measures should be taken by employers to ensure that people do not come into contact with work equipment and the materials therein likely to burn or scald Clear layout of controls, e.g. for starting, or making a change in operating conditions and readily identifiable and readily accessible emergency stops All work equipment should be provided with means to isolate it from its source of energy Work equipment should be sufficiently stable to avoid risk to health or safety Places where work equipment is used should be adequately lit by appropriate means in line with the work to be carried out It should be possible to carry out maintenance operations while the work equipment is stopped. If this is not possible then other protective measures should be taken Work equipment should have appropriate markings for purposes of health and safety Work equipment should have appropriate warnings or warning devices for purposes of health and safety. Page 21 of 32
15. Identify two mechanical and non mechanical hazards presented by bench top grinder (8) Mechanical hazards Contact with the rotating wheel Drawing into the trap between the tool rest and the wheel Ejected parts from the machine or materials Non-mechanical hazards Dust Electricity Ergonomics Fire / sparks Noise Stability of the machine Vibration 16. Identify mechanical and non mechanical hazards associated with cement mixer in a construction industry (8) Mechanical hazards Entanglement Trapping between fixed and moving parts at rear Non-mechanical hazards Chemicals (corrosive cement) Dust Electricity Ergonomics Manual handling Stability of the machine Temperature 17. Outline the general precaution should be taken for portable power tools (8) Never carry a tool by the cord or hose Never pull the cord or the hose to disconnect it from the receptacle Keep cords and hoses away from heat, oil, and sharp edges Disconnect tools when not in use, before servicing, and when changing accessories such as blades, bits and cutters Keep all observers at a safe distance away from the work area Secure work with clamps, freeing both hands to operate the tool Avoid accidental starting – the operators should not hold a finger on the switch button while carrying a plugged-in tool; Use RCDs or similar with electrical supplies to portable tools Ensure good footing and maintain good balance Page 22 of 32
Wear appropriate PPE – loose clothing, ties, or jewellery can become caught in moving parts Maintain tools- they should be kept sharp and clean. Follow the user manual instructions for lubricating and changing accessories Regularly inspect tools and report defects and Remove damaged portable electric tools from use. 18. Identify advantages and disadvantages of interlocked guards (8) Advantages Interlocked guards Allow ready safe access for material feeding Are convenient to use Are less likely to be deliberately defeated than fixed guards where frequent access is required Speed up operations Limitations Interlocked guards Increase the complexity of the machine Are difficult to test and maintain May need a brake or timed delay where machinery does not stop instantly Rely on components which could fail in service Require regular maintenance and testing May not fail to safety, i.e. failures may not be apparent until it is too late which can give a false sense of security. 19. Identify advantages and disadvantages of two hand control devices (8) Advantages Allow full visibility and access to the machine Are a simple inexpensive design Limitation Require operator discipline and training Only protect the operator, therefore, are only suitable in restricted areas Are easily defeated
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ELEMENT 4: ELECTRICAL HAZARDS AND CONTROL Short Questions 1. Outline the first-aid treatment that should be given following an electric shock. (8 marks) Action to be taken following an electric shock: Break any contact using non-conductive material or isolate the supply. Artificial respiration should commence immediately and continue until either the victim recovers or medical staff intervenes. Emergency medical attention should always be sought, as there is a risk of internal injury. 2. Identify and describe FOUR protective systems that can be incorporated within an electrical circuit. (8 marks) The following protective systems can be incorporated within an electrical circuit: Fuse – acts as a weak link. Circuit breaker – acts as a weak link. Earthling – prevents current from being carried. Isolation – physically separates the electricity from the power source. Switching off – deprives the equipment of power whilst Remaining connected to the supply. Low voltage using a transformer – reduces the effect of any shock. Residual current device Double insulation – encloses the item from danger. 3. Outline the practical measures to reduce the risk of injury from electricity when using portable electrical tools on a construction site. (8 marks) The following practical measures should be used to reduce the risk of injury when using portable electrical tools: Use of reduced voltage by means of a 110v centre tapped step down transformer. Use of double-insulated (class II equipment) or battery operated (cordless) equipment. Use of tools with residual current devices which protect individuals by rapidly disconnecting the power in the event of a fault occurring. Ensuring earth continuity Ensuring frequent and regular testing Avoiding use in wet conditions/weather. Carrying out regular visual inspections and user checks (Note: The context given is in the use of the equipment on a construction site, but this could equally be in any other remote area where similar conditions apply.)
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4. Outline FOUR control measures relating to the safety of electrical appliances. (8 marks) Control measures relating to the safety of electrical appliances are: Proper selection of suitable equipment The use of protective devices Effective inspection and maintenance by competent persons Visual user checks 5. (a) Describe the possible effects of electricity on the body. (4 marks) The following effects may be seen on the body on contact with electricity: Burns are the most likely effects with the main sites of damage being entry and exit points of electricity with possible damage to internal organs. Other effects could include interference with nerve and muscle action which leads to involuntary grip and cardiovascular effects, leading to disruption of heart rhythm and possibly death. (b) Outline FOUR factors that may affect the severity of injury resulting from contact with electricity. (4 marks) Electricity includes: The nature of the current (AC/DC) The frequency and level of the current The length of time that the current flows through the body The voltage involved Individual body resistance due to age, sex, sweat on the skin surface and existing medical conditions 6. A 30-year-old joiner received an electric shock from a hand-held 230v drill while fitting wooden floorboards in a new construction. The drill was five years old and had never been tested. The joiner was not seriously injured. (a) Identify the factors that may have limited the severity of injury this time. (4 marks) Factors leading to limitation of the current: High earth path resistance due to wooden floor or dry conditions The age and health of the joiner The lengths of contact time – possibly reduced by speed of action of fuse or contact breaker (b) Outline the physical effects on the body that the electrical contact could have caused under different circumstances.(4 marks) Physical effects on the body: Burns - main sites of damage being entry and exit points of electricity with possible damage to internal organs. Interference with nerve and muscle action - results in spasm and/or involuntary grip, cardio-vascular effects, e.g. cardiac arrhythmia, respiratory arrest and possibly cardiac arrest and death in severe cases. Page 25 of 32
(c) Describe the types of inspection and/or test that the drill should have had. Also, identify the features that should be checked by EACH type of inspection and the factor that might affect the frequency of examination/test. (12 marks) Three types of inspection exist at differing levels of importance: First – carried out by the user (joiner). Visual check of general condition for damage or overheating, integrity of plug, socket and cable should be carried out at every use. Second – formal, periodic, visual inspection - weekly or monthly dependent on amount of use and conditions of use Inspect equipment, connectors (plug, socket) and cable Also check correct fuse rating. Third – carried out by competent person, at three monthly, six monthly or yearly intervals dependent on extent and conditions of use. Combined inspection and test (PAT) Checks that the equipment is working correctly and for potential faults, e.g. loss of earth integrity, deterioration of insulation and possibly contamination of internal and external surfaces 7. When using hand-held electrical tools at 220 – 240v AC, such as in a factory workshop: (a) Outline the possible hazards. (8 marks) Possible hazards when using 220-240V, hand-held electrical tools are: Electric shock Burns Arcing Explosion Secondary effects, such as falls (b) Describe the suitable precautions that should be taken to control these hazards. (12 marks) Hazards: Reduced voltage Fuses Residual current devices Earthling Double insulation Testing Visual inspection Favourable environmental conditions
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8. List the items that should be included on an inspection checklist designed to ensure the safety of portable electrical appliance The main areas to consider when looking for the dangers in the use of portable electrical equipment are: The plug No fuse or fuse replaced by nail, etc Damage to plug casing Incorrect wiring inside plug Earth wire detached from connection The cable / lead Being run over by vehicles Dragged over rough surfaces Trapped in machinery Exposed to hot surfaces or corrosive chemicals Continuous flexing Insulation failure The joints and connections Makeshift, temporary connections Lead pulled out or cord grips Connections wired incorrectly so that metal work becomes live Wrong connections Poor earth connections preventing fuse from working The appliance Damaged casing Worn or damaged connections 9. Outline a range of check that should be made to ensure electrical safety in an office environment Precautions for electrical safety in office environments could include: Equipment is of approved standard e.g. BS/EN Standard Maintenance of fixed electrical installations There is a means of isolation All connections, wiring free from damage Correct fuses Plug correctly wired Avoid overloading of outlets Switch off appliances when not in use Maintain good housekeeping around electrical equipment Page 27 of 32
If required portable appliance testing in date System not overloaded Cables correctly routed to avoid hazards RCDs used System for reporting defects
10. Describe the function and limitation of a fuse as an electrical protection device (8) A fuse is a weak link designed to melt, breaking the circuit at excessive currents. The fuse is intended to protect the equipment and wiring from over currents and will not protect the people from electric shock. The flow of electric current generates heat. The higher the current, the more the heat. Fault currents caused by a short circuit, e.g. to earth, are likely to allow much higher currents to flow than the equipment or wiring was designed to carry. Without a fuse the equipment might become damaged, the wiring would eventually become hot enough to melt its insulation and start a fire. Advantages Cheap and readily available Relatively easy to place Protects equipment from overload Disadvantages Will not protect individuals from electric shock Slow to operate Inaccurate Can be replace with unsuitable or wrongly rated fuse Easy to override Needs screwdriver or similar tool to replace 11. Describe the principles of operation of the following types of electrical protection 1. Earthing 2. Reduce voltage Earthing Electricity will always try to reach zero potential, i.e. earth. Earthing of conductive materials, e.g. metal workbench, sinks and metal pipe work provides a low resistance path to earth, lower than a human body. Earthing of exposed metal parts, which should not normally carry current, ensures that under fault condition a higher than normal current can flow, causing the fuse to overheat , melt, and the break the circuit.
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Advantages May prevent indirect electric shock by providing a very low resistance path to earth Readily identified Disadvantages Requires specialist testing and maintenance with professional installation Protection defeated if removes Reduced voltage Reduced voltage systems are recommended in all situations where there is risk of mechanical damage to equipment and cables. By reducing the voltage present the consequences of electrical shock can be greatly reduced. Advantages As available voltage difference is 55V ac injury is highly unlikely Colour coded cabling system for easy recognition Disadvantages Specialist equipment required for 110V Lead from supply to transformer will be protecting with a RCD 12. Outline practical measures to reduce the risk of electrical shock when using portable electrical appliances The precautions required to prevent accidents using portable equipment are: Reduced voltage operation Use of residual current devices Apparatus and cables should be protected against overload by fuses and or circuit breakers All cables should be insulated and protected against mechanical damage Correct types of sheathing to suit working conditions Sufficient socket outlets to minimise the need for trailing cables The use of cable drums wherever possible The use of cable drums wherever possible Correct maintenance and repair Correct connections Regular inspection and checks to remove damaged equipment Properly trained operators
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13. In relation to electrical safety, explain the meaning of the following terms 1. 2. 3. 4.
Isolation earthing Double insulation Over current protection
Isolation Isolation means shutting off the electrical supply to an item of equipment or part of an electrical system and preventing the system being mistakenly reconnected and is used for example during maintenance work. Advantages Safest option in that it eliminates the electricity May be physically locked off Disadvantages It may isolate other equipment May be reconnected unless locked off Prevents live fault finding Earthing Electricity will always try to reach zero potential, i.e. earth. Earthing of conductive materials, e.g. metal workbench, sinks and metal pipe work provides a low resistance path to earth, lower than a human body. Earthing of exposed metal parts, which should not normally carry current, ensures that under fault condition a higher than normal current can flow, causing the fuse to overheat , melt, and the break the circuit. Advantages May prevent indirect electric shock by providing a very low resistance path to earth Readily identified Disadvantages Requires specialist testing and maintenance with professional installation Protection defeated if removes Double insulation Double insulation is where two separate layers of insulation are provided. This allows of insulation are provided. This allows for fault detection where one layer has failed but the second layer still provides protection for the user. Page 30 of 32
Advantages Two layers prevent contact with live parts No earth required Disadvantages Damage to equipment casing defeats double insulation No earth therefore no protection if used with equipment that requires earth. Over current protection Over current protection is a method of preventing the flow of excess current by cutting the supply under fault conditions by means of a fuse or circuit breaker. 14. Identify the advantages and disadvantages of RCD RCD provide protection against leakage to earth and consequential risk of shock by comparing the electricity flow to the equipment with the return flow to the equipment with the return flow along the neutral wire. If any difference is detected the equipment is isolated. Advantages Rapid response Difficult to defeat Easy to use, test, and reset Cannot be reset with a fault on the circuit Disadvantages May isolate other important equipment Mechanical device which could fail No overload protection 15. In relation to the use of electrical cables and plugs in the workplace: 1. Identify FOUR examples of faults and bad practices that could contribute to electrical accidents 2. Outline the corresponding precautions that should be taken for EACH of the examples identified in 1. 1.Failure to select the right equipment for the environment (e.g. armoured or heat resistant cable might be required in arduous conditions) Incorrect rating of fuses Ineffective or discontinuous earthing Overloading of socket outlets Cables unnecessarily long (or short) Page 31 of 32
The use of coiled extension leads Poorly wired plugs (e.g. wires under tension or outer protective sheath not clamped) The use of defective cables or plugs
2.
Earthing Calculate correct rating for a fuse RCD residual current device Reduced voltage Battery powered Double insulation
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