NEBOSH – IGC 2 QUESTION BANK

2012

ARBRIT

NEBOSH – IGC 2 QUESTION BANK


CONTROL OF INTERNATIONAL WORKPLACE HAZARDS

Element 1: Workplace Hazards and Risk Control

1) A three metre deep trench has to be dug across a car park.

a) Identify the hazards associated with the work.

b) Outline the control measures to reduce the risk.

Answer:

a) Hazards associated with work may include:

• Unexpected collapse of the trench wall /cave in: Sudden collapse of the excavation walls normally happens due

to the condition of soil, presence of water, vibrations due to activities in the vicinity, lack of support etc. Severe

crush injuries can result from even relatively small collapse as soil is very heavy

• Falling of persons / workers into the trench: Falling of persons normally happens as a result of unfenced edges

or while climbing in to or out of the excavation from ladders

• Presence of toxic gases during the trenching: Excavations can get filled with any gas that is heavier than air or

other gases in the surroundings can get leach out of the soil and into excavation

• Accumulation of water: Flooding usually happens from surface water due to heavy rain, ground water or due to

the rupture of water pipelines.

• Fire due to the presence of underground utilities carrying flammable materials

• Collapse of the adjacent structure: Excavation works can affect the foundations of nearby buildings causing

destabilizing or collapse of the structure

• No proper access/ egress

• Mobile equipments falling into the pit

(b) To avoid the unexpected collapse of the trench / excavation wall, the wall should be protected by means of sloping,

shoring, benching or shielding. Check for the presence of underground utilities before the start of the work. The plans of

the area of the excavation should be obtained. The buried services should be located using surface clues and detection

equipment. The buried services should be uncovered by careful digging with hand. The perimeter of the excavation

should be protected by means of hard barrication so as to avoid the unauthorized entry of personnel into the work area

and to avoid the vehicles running close to the excavation. The pit / excavation should be monitored to detect the

presence of toxic gases as well the availability of oxygen. Accumulated water inside the excavation / trench should be

removed and protected against the runaway water. Proper lighting and caution boards should be provided in and

around the excavation area. The excavation should be made subject to a permit to enter. Forced ventilation, air

monitoring and respiratory protective equipment may be necessary. Excavation should always be inspected by a

competent person


2) Identify the safe working practices that could be considered to reduce the risk when using a mobile tower scaffold.

Following factors need to be considered when using a mobile tower scaffold:

� Guard rails must be fitted on the work platform

� Tower must not be over loaded

� Wheels should be locked when the tower is in use

� Tower must be sited on firm and level ground

� People and materials should not remain on the tower when it is moved

� Care should be taken to avoid the over heads when the tower is moved

� Outriggers should be used where necessary to ensure stability

� Mobile tower should be build by trained workers

� Tower platforms should be fully decked

� Castor wheels should have adequate strength

3) Identify the main hazards that may be present during the demolition of a building

Some of the hazards that may be presented during the demolition of the building may include the following:

� Unintentional collapse of the building being demolished or the adjoining structures because of the lack of

temporary support, build up of debris, weakening of load bearing sections etc.

� Debris falling from height during the demolition

� Fires, explosion, electrocution etc. due to services not being isolated

� Health hazards from chemicals, asbestos, lead based coatings, biological contaminations etc.

� Personnel falling due to unsafe place of work or due to improper access / egress

� Hazards related to the use of explosives

� Hazards related to the manual handling of heavy loads

4) Identify the precautions that should be considered to prevent accidents to children who may be tempted to gain

access to a construction site.

Some of the precautions that should be considered to prevent the entry of the children into the construction sites are:

� Fencing / Barricading the site

� Fencing / Covering excavations/ trenches

� Display of warning signs and caution boards

� Visiting the neighborhood and informing the parents about the work activities

� Visiting the schools and conducting awareness programs

� Monitoring by the use of security patrols and closed circuit televisions

� Posting caution boards near excavated pits and dangerous machinery

� Removing ladders and denying access to the scaffoldings


5) Identify the safe working practices for the use of mobile elevated work platform (MEWP)

The safe working practices that need to be followed while using a mobile elevated working platform include:

� Operated by a trained, experienced and competent operator

� Operated on a firm and level ground

� Do not overload it

� Cordon the area when in use.

� Outriggers fully extended.

� Ensure no overhead obstruction

� Do not operate under overhead electric lines

� Move the equipment keeping the platform low.

� Before use check whether the brakes, limit switches are in working condition.

� Safe working load be displayed

� It should be inspected as an item of lifting equipment designed to carry people.

6) (a) Identify four health effects of working outside in extreme heat created by the sun

(b) Outline the control measures that could be used to reduce the effects of the sun on construction workers

(a) Working on the hot and humid climatic conditions usually has large impacts on the health of the workers. Some of

the effects of the temperature on the human body are listed below:

� Sun Burns – Too much of exposure to sun or working in humid conditions can cause reddening of the skin along

with painful / blistering peeling of the skin

� Heat Exhaustion – Working in hot or humid climatic conditions may cause fluid loss in the form of sweating

which also causes loss of salt from the body. Inadequate water intake under these circumstances causes body

cooling system to break down

� Heat Rashes – Exposure to humid conditions can cause red bumpy rash with severe itching on the skin

� Fainting – Fluid loss and inadequate intake of water can cause dehydration which can result in fainting.

� Heat Stroke – When the human body has used up all its water and salt reserves it will stop sweating which can

result in stroke.

(b) Remove or reduce the source of heat where ever possible, control the temperature using engineering controls e.g.

change the processes, use fans or air conditioning, use physical barriers that reduce exposure to radiant heat. Providing

periodic breaks and rest facilities in cooler conditions and by circulating cool drinking water for the workers prevents

them from dehydration. Allow the workers to work in shifts so that they may not be fully exposed to the humid

conditions. Provide suitable personal protective equipments to the workers. Prevent employees who are more

susceptible to heat stress either because of an illness or medications that may encourage the early onset of heat stress.

7) Outline prevention strategies an organization could consider to reduce the risk of violence towards workers.

Queue management and information, Change the job to give less face to face contact, Use cheques, credit cards, tokens

instead of cash, Check credentials of "clients" and meeting locations, Avoid lone working in high risk areas, Call-in system

for lone workers, Arrangements to get staff home if working late, Training employees to deal with aggression, Changing

public waiting areas, Video cameras, alarm buttons, visible security staff, Protective screens and coded security locks,

keeping record of past incidents and vetting customers, security doors between public areas and staff areas.


8) Repair work is to be carried out on the roof of a school

a) Identify the control measures to reduce the risks to roof workers.

b) Identify two control measures to reduce the risks to other persons.

Answer:

1) Provide edge protection around the roof perimeter

2) Cover or guard the openings on the roof

3) Use crawler board on slope fragile roof

4) Provide proper access and egress to the roof

5) Tie safety net below the roof

Protections for preventing material fall from height:

1) Materials shall be lowered from height, no material shall be dropped.

2) Do not keep any loose materials unsecured on the roof

3) Tie the tools used for roof work to the waist

4) Sheets shall be secured and kept on roof.

PPEs:

1) All employees should appropriate PPEs like Safety helmet, gloves, Safety Harness etc.

2) They shall wear spectacles when working under hot sun on a GI sheet work.

Employees:

1) Employees send for the roof work should be selected and trained

2) Employees selected for the job should undergo premedical test.

3) Establish Height work permit

4) Appropriate rest pause should be introduced.

9) a) Identify four hazards that cause slips and trips.

b) For the hazards identified above, outline the control measures that can be used to control the risk.

Answer:

a)

� Floor Surface: Slippery floor, holes on the floor, uneven floor, smooth floor

� Contamination: Spillages, Leaks

� Obstructions: Rubbish, trailing cables, rugs etc.

� The Task: Carrying loads, space to work

� Environment: Lighting

� Footwear: Unsuitable footwear

� The People: Unaware of the dangers

b)

� Risk Assessment: Conduct a risk assessment on the path of the peoples movement to identify the hazards and

take actions.

� Floor Surface: Provide Non Slipper y floor and even floor ; ensure no pot holes on the floor; Contamination:

Ensure no Spillages and Leaks of water, grease , oil on the floor


� Obstructions: Keep the Rubbish & its bins at the side of the path, route the trailing cables so that it does not

obstruct the path, ensure no loose rugs placed which would cause trip etc.

� The Task: Ensure employees carry loads not more than their capacity. Loads carried do not block their view. Give

them enough rest pauses if the load is carried for long distance. Provide enough space to work.

� Environment: Provide enough Lighting at the passages

� Footwear: Provide suitable footwear or inform them to wear appropriate foot wears.

� The People: Make employees aware of the hazard on the path they move.

� Designated walkway: Provide designated walkway for people movement.

� Reporting: Inform employees to report hazards they noticed to the management

11) Identify the possible control measures for the erection of an independent tied scaffold

� Scaffolds should always be erected under a competent supervisor.

� Only experienced and trained employees be deployed for the work

� No damage scaffold material to be used.

� Factor of safety for all components on a scaffold is 4.

� Ground shall be even, firm, and capable of carrying the scaffold weight.

� Unstable objects such as barrels, boxes, loose brick or concrete blocks shall not be used to support scaffold base.

� Base plate shall be used to spread the load of the scaffold.

� All scaffold posts (standards) shall be pitched on steel base plates.

� Screw jacks shall be used to compensate for variations in ground level.

� Scaffold posts and frames shall be erected and maintained vertical and plumb and vertically braced in both

directions to prevent swaying and displacement.

� Adequate Ties or guys shall be provided to meet the design requirements of the scaffold.

� Every scaffold platform shall be closed planked or decked as fully as possible between the guardrails.

� Platforms shall be kept free of obstructions, unnecessary materials, projecting nails and other unnecessary

tripping hazards (including uneven decking).

� Adequate space for workers to safely pass shall be provided and maintained wherever materials are placed on

platforms or if any higher platform is erected thereon.

� Platform units that have become slippery with oil, sand, or any other substance shall be cleaned, or otherwise

removed and replaced, prior to continuing use

Element 3: Musculoskeletal Hazards and Risk Control

1) A worker is manually loading boxes of components onto metal shelves.

(a) Identify four types of injury that the worker could suffer while carrying this activity.

(b) Identify the factors in relation to the task that could increase the risk of injury.

(c) Identify the factors in relation to the load that could increase the risk of injury.

Answer: (a) The injuries that could be possible while performing a manual handling includes:

� Muscular sprains and strains

� Back Injuries

� Trapped nerve


� Hernia

� Work Related Upper Limb Disorder

� Cuts, Bruises and Abrasions

� Fractures

(b) The factors that need to be considered with respect to task while performing a manual handling includes:

� Does the task involve twisting and stooping

� Does the task involve pushing or pulling

� Is the task very repetitive

� Does the task involve lifting the load through a vertical distance

� Rest breaks provided while performing the task

� Is a long carrying distance involved

� Does the task involve lifting the load above the shoulder height

(c) The factors that need to be considered with respect to load while performing a manual handling includes:

� Size, Shape and Volume of the load

� How heavy the load is

� Gripping facility available in the load

� Does the load to be carried have sharp edges

� The temperature of the load to be carried

� The stability of the load to be carried

� The centre of gravity of the load

� Stacked method of the load

2)

a) Outline the possible risks to health associated with the use of Display screen equipment (DSE).

b) Identify the features of a chair to ensure it is suitable for use at a DSE workstation.

Answer:

a) The possible health risks associated while using display screen equipment includes:

� Musculoskeletal Disorder or WRULD: Which normally occurs as a result of the repetitive use of the keyboard and

mouse for long periods of time

� Eye Problem: Temporary eye fatigue associated with prolonged use of the screen

� Fatigue and Stress: Associated with the type of work being done

� Radiation

b) The features of chair that need to be used in a display screen equipment work station include:

� It should have Good lumbar support

� Seat should be have Good width and depth

� Chair should be adjustable height wise and the back also.

� It should have Stable base

� It should have provision swivel

� Availability of arm rests


3) Outline eight precautions that should be taken when leaving a forklift truck unattended.

The precautions that need to be considered when leaving a forklift truck unattended includes the following: Park it at

designated areas, Apply brakes before leaving the forklift, and Keep the controls in neutral position, Switch off the

engine once it is parked, Remove key & return it to the responsible person, Forks shall rest on the floor, Mast shall be

tilted slightly forward, Do not park the forklift so that it obstructs the walkway, Parked forklift should not obstruct fire

exits/fire points.

4) Outline the precautions that should be taken when performing a lifting operation using a crane.

Proper slinging methods need to be adopted while performing a lifting operation, use tag lines attached to the load so as

to avoid the swinging of the load during lifting due to the presence of wind. Avoid impact or jerk load as it may affect the

stability of the equipment and also may cause swinging of the load during the lifting operation. Remove all the loose

materials present during lifting so as to avoid it from falling. If the load that need to be lifted have sharp edges proper

packing’s need to be provided to avoid load from cutting the slings and lower the load into packing so as to avoid the

crushing of the slings by the load. Loads should be distributed to all legs of the slings and never leave a load suspended.

5) Forklift trucks are operating in a busy workplace

Identify suitable control measures to reduce the risk of collision with the workers.

Answer:

1) Segregation if possible: A different path is provided for vehicle and people movements

2) Separate routes: If different path is not possible, then designated path way is provided.

3) Provide Median: Provide solid median for opposite vehicles movement or establish “one way” movement

of vehicles.

4) Clearly marked routes: The paths should be clearly marked to show pedestrian path and vehicles.

5) Clear direction signs and door marking: Adequate & appropriate sign boards are fixed on the path

showing clear signs of direction, warning etc.

6) Gangways suitable width and clearance: The vehicle path and the peoples are path are of adequate width

for easy movements of both.

7) Speed limits: Install speed limits wherever required.

8) Adequate lighting: The pathway is well lit.

6) Identify the factors to be considered in an ergonomic in an ergonomic assessment of a display screen equipment

workstation

1) Provide adequate lighting

2) Avoid glare or reflections from the screen

3) Comfortable temperature

4) Adequate working space should be ensured

5) The Chair must be of the swivel type and have five or more castors. The height of the seat should be

adjustable. The height and rake of the back rest should also be adjustable. If the chair has arms, they should


be either adjustable or in such a position as to not restrict movement. The chair must allow the user to

obtain the recommended ergonomically correct seating posture.

6) The Chair must be of the swivel type and have five or more castors. The height of the seat should be

adjustable. The height and rake of the back rest should also be adjustable. If the chair has arms, they should

be either adjustable or in such a position as to not restrict movement. The chair must allow the user to

obtain the recommended ergonomically correct seating posture.

7) A foot-rest is not necessary unless the user is unable to place his/her feet comfortably flat on the

floor. The foot-rest should be adjustable to individual requirements.

8) Document holder should be stable, adjustable in height and angle and be placed close to the screen to

minimize head movement.

9) The Screen: The characters on the screen should be stable and free from flicker, of suitable size and

adequately spaced. The contrast and brightness of the screen should be easily adjustable. The screen should

tilt and swivel easily. The screen should, if practicable, be placed at right angles to any windows and parallel

to overhead lighting. The top of the screen should normally be just below eye-level

10) The Keyboard: The keyboard should be adjustable in angle. The key symbols should be adequately

contrasted. There should be sufficient space in front of the keyboard for the user to rest his/her wrists

and/or arms.

11) The Software: The software should perform the task required of it. It should provide feedback on the

performance of the system. The software should be reliable; software that “crashes” frequently causes

unnecessary stress to the user.

7) Outline the specific hazards associated with the use of battery powered forklift trucks and identify the precautions

necessary in each case.

The specific hazards associated with the battery powered forklift trucks are: Charging batteries emit hydrogen gas which

is explosive; Batteries contain dilute sulphuric acid which is corrosive in nature; Batteries are extremely heavy thereby

causing manual handling risk; Electricity can cause arcing, shock, burns or fire; Battery contents are environmental

hazard requiring appropriate disposal; Battery leads can short and result in burns and electric shock

The precautions that can be used may include: Batteries must be charged in well ventilated areas only away from the

ignition sources; Sulphuric acid should be handled wearing appropriate personal protective equipments; Battery

handling should be mechanized; Electrical risk may require the use of insulated tools and gloves

8) Outline the precautions that should be taken when using the mobile cranes

Crane Suitability: Safe working load of the crane be more than the load being lifted : Ground Conditions: Firm and even

ground condition: Outriggers : Outriggers be extended fully: Obstructions: Ensure no obstruction when lifting or

swinging he material: Overhead Power Lines: Ensure no overhead lines above the crane: Limit Switches Hoist, Boom

limit switches are functioning: Suitable lifting tackle: Tested and suitable lifting tackles shall be used: Slinging Method :

Proper slinging methods adopted so that the load is balanced when lifting: Travelling with load : Avoid travelling with

load as far as possible: Good Visibility : Ensure good visibility for the operator: Communications : Standard

communication be established and known to all concerned: Environment: Work during daylight and not under heavy

wind: Competent Operator: Competent Operator be deployed: Signal Man : Post a signal who knows the standard

signals with visibility jacket: Rigging Gang: Experienced and Trained rigger be deployed


Element 4: Work Equipment Hazards and Risk Control

1) a) Identify four mechanical hazards associated with the use of pedestal drill.

b) Outline four control measures to reduce the risk of injury to operators of pedestal drills.

2) Outline four main categories of guards and safeguarding devices that may be used to minimize the risk of contact with

dangerous parts of machinery.

Moving machine parts have the potential to cause severe workplace injuries, safeguards are essential for protecting

workers from these preventable injuries. Some of the safeguarding that may be used on the machines may include:

Fixed Guards – which forms the permanent parts of the machines, these types of guards is usually preferable to all other

types because of its relative simplicity and performance: Adjustable Guards – These guards can be adjusted according to

the work or workplace. It is important that such guards are properly adjusted and maintained for them to be effective:

Automatic Guards – These guards are self adjusting and can be automatically moved into position as the machine or

cycle starts: Self adjusting guards – These types automatically opens and closes as the work piece is put in and pulled

out: Interlock guards – When this type of guard is opened or removed, the tripping mechanism or power automatically

shuts off or disengages, the moving parts of the machines are stopped and the machine cannot cycle or be started until

the guards are back in place

The different types of safe guarding devices that may be used may include the following: Presence sensing devices – The

photo electric presence sensing device uses a system of light sources and controls which can interrupt the machines

operating cycle: Pullback devices – Pull back device utilizes a series of cables attached to the operators hands, wrists and

arms. This type of device is primarily used on machines with stroking actions. Safety trip controls: Safety trip controls

provide a quick means for deactivating the machine in an emergency situation: Two hand controls – Concurrent use of

two hands on separate controls prevents hands from being in danger area when the machine cycles starts. The two hand

control requires constant, concurrent pressure by the operator to activate the machine.

3) A pedestal electric drill is being used on a building site.

a) Other than electricity, identify four hazards associated with the use of the drill.

b) Outline four precautions that could be taken to reduce the risk to workers.

a) The other hazards associated with the use of pedestal drills are: 1) Entanglement with the rotating drill bit or chuck 2)

Stabbing or puncture by the drill bit during normal use or if the drill bit breaks 3) Drawing in at nip points between the

motor and the drive mechanism 4) Puncture can result from the swarf ejected during the metal cutting 5) Hot surfaces

can result in burns 6) The cutting fluids used for the operation can cause dermatitis 7) Noise generated during the

operation

b) The precautions that can be used may include: By providing the fixed guards over the motor and drive mechanisms

can avoid hazards like entanglement and drawing in, Adjustable guards can be provided over the chuck and the drill bit,

Eye and hearing protection may be necessary, routine maintenance including inspection and portable appliance testing,

Using trained and competent operators.

4) Identify eight types of non mechanical hazards associated with the use of machinery.

Machinery may also present other hazards and suitable measures need to be taken to prevent the injury. Some of the

non – mechanical hazards are:

� Electrocution to the workers can happen if they come in contact with the naked wires or other electrical parts /

connections of the machine

� Burns result on contact with the hot parts of the machine


� Dust and fumes from the point of operation or from the exhaust systems

� Fire / Explosion due to leakages of fuel

� Noise and vibration

� Radiation from the activities done on the machine

� Flying chips and sparks from the point of operation

� Hazardous chemicals

� Manual handling

5) a) Identify the hazards associated with the use of a cement mixer

b) For the hazards identified above, outline the control measures that can be used to reduce the risk.

(a)

� Entanglement with the rotating parts of the machinery

� Trapping of the body parts or clothes inside the moving parts

� Drawing in at nip points between motor and drive mechanism

� Crushing between drum and drum stop when tipping

� Friction or abrasion on contact with moving drum

� Ergonomics and Manual handling injuries

� Health hazards due to dust inhalation and contact with the wet cement

� Electrocution

� Noise and Vibration

� Ejection of materials while working

(b) To protect the workers from the above mentioned hazards, the following control measures should be taken into

consideration. Cement mixer should always be located on a firm and level surface. It should be placed away from the

ongoing traffic or should be cordoned so as to avoid collision with other vehicles. The rotating parts or other moving

parts of the machinery should be protected by means of adequate guards or body coverings. Safe storage of petrol and

control of ignition sources for petrol powered equipment. Routine inspection and portable appliance testing and use of

residual current device for electrically powered equipment. Provide workers with ear plugs / muffs to protect them

against the noise generated by the mixer. When removing the drum for storage or transportation makes sure the

machine is properly switched off and unplugged. Avoid putting anything like hand, shovel or anything other than the mix

into the drum while it is rotating.

6) Outline the hazards and risks to which a worker could be exposed when cutting down a tree using petrol driven

chainsaw.

Worker performing such an activity by using petrol driven chain saw may be exposed to different types of hazards like:

his hand or body may suffer cut injuries upon contact with the moving blade, Body parts or clothing may get entangled

with the moving blade, Drawing in may happen at the nip points between the blade and the casing, Penetration or

puncture injuries my result due to the ejected parts, Burns may happen as a result of contact with the hot surfaces of

the equipment, High noise and vibrations involved during the activity can result in risks to health. Since petrol is used as

a source of power there can be chance of fire and explosion. The dusts and smoke generated during the activity can

cause health hazards. Performing the task in awkward pose can result in ergonomic hazards to health.

7) Outline control measures to reduce the risk to workers when using non – powered hand tools.

The control measures that can be used to reduce the risk to workers when using a non powered hand tools may include:

Tools must be suitable for the task that they are going to perform and for the environment in which they are to be used.

Tools should be visually inspected routinely before use to ensure that they are in an acceptable condition. Users should

be given appropriate information, instruction and training. Tools should be maintained in a safe condition. Good

supervision should be ensured.


Element 5: Electrical Safety

1) Outline the precautions that should be taken to reduce the risk of harm from electrical equipment in a workplace.

2)

a) Identify the effects on the human body from a severe electric shock

b) Identify four factors that could affect the severity of injury resulting from contact with electricity.

c) Outline how earthing can reduce the risk of receiving of an electric shock

Answer:

a) The effects on human body due to severe electric shock can be: Tingling sensation, muscle tremor, inability to

breathe, ventricular fibrillation, cardiac arrest, extreme muscle contractions, internal and external burns at contact

points, uncoordinated heart beat and possible death.

b) Resistance or the conductivity of human body (Higher the resistance less the severity): Duration of contact (higher the

duration higher the severity): Path of the electricity through the body e.g. hand to foot or ear to ear etc. (it could be

dangerous if current flow takes place through heart): The conductivity of the surrounding environment - The ease with

which current can find a path to a lower potential, usually earth: Contact area of human body (higher the contact area

higher the amount of current flow, hence higher the severity of shock)

c) ELECTRICAL GROUNDING is a safety measure used to help prevent people from accidentally coming in contact with

electrical hazards. Grounding can be considered as a connection from an electrical equipment and wiring systems to the

earth by a wire or other conductor The primary purpose of grounding is to reduce the risk of serious electric shock from

current leaking into un insulated metal parts of an appliance, power tool, or other electrical device. Grounding is also

used in manufacturing industries to prevent accumulation of hazardous static electrical charges

3) Identify the emergency action to take if a person suffers a severe electric shock

• On finding people suffering from electric shock raise the alarm by calling for help from colleagues

• Switch off the power if it is possible

• Call for an ambulance

• If it is not possible to switch off the power then push or pull the person away from the conductor using an object

made from a good insulator.

• If the person is breathing place him or her in the recovery position so that an open airway is maintained.

• If the person is not breathing apply mouth to mouth respiration and in the absence of pulse chest compression

should be provided.

• Treat any burns by placing a sterile dressing over the burn and secure it by means of a bandage.

• Remain with the person until they are taken to a hospital


4) Identify the electrical hazards that could be discovered by a visual inspection.

The electrical hazards that could be discovered during a visual inspection include: Damage in the body of the plug,

Damage in the body of the appliance, Plug cable clamp appears to be loose, Double insulation wire with splits or severe

kinks / pinches, In adequate grounding,

5) Outline the range of checks that should be made for electrical safety in a workplace

Element 6: Fire Safety

1)

a) Identify four sources of ignition that may lead to a fire in the workplace

Answer:

1) Electrical faults (poor connections, damaged insulation, overloaded circuits etc.)

2) Friction (hot bearings etc.)

3) Foreign Substance ( Tramp metal that produces spark when struck by rapidly moving parts of machinery)

4) Open Flames (cutting & welding torches etc.)

5) Smoking and matches

6) Spontaneous ignition (coal stacks, oily waste etc.)

7) Hot Surfaces (hot ducts of flues, electrical lamps etc.)

8) Combustion Sparks (Rubbish burning, Furnaces etc.)

b) Outline methods of reducing the risks of a fire in the workplace

The best course of action to ensure fire safety is to prevent fires from starting. Fire prevention can be achieved by

controlling the fuel sources, controlling the ignition source, controlling the oxygen sources.

The best method of reducing the risk of a fire in the workplace is to eliminate the flammable material entirely from the

workplace. This can be achieved by disposing of the old stocks of flammable material that are no longer needed. It is

possible to substitute one potential source with another that present less of a fire risk. If the flammable materials cannot

be eliminated or substituted then the quantities of these materials present in the workplace should be minimized. For

the flammable materials that remain arrangements must be made for the safe usage and storage. Control of the ignition

source – Electrical equipments should be routinely inspected and tested to ensure that it is safe for working, Hot works

should be controlled with a permit to work system, Smoking should be controlled in the workplace, Mechanical heat

should be controlled by routine maintenance, Deliberate ignition can be controlled by making good security

arrangements for the workplace. Systems of work must be designed to minimize fire risk. Good housekeeping should be

maintained to ensure that the workplace is waste free, tidy and in well order.

c) Outline the measures that should be in place for a successful evacuation of a workplace in the event of a fire.

The measures that should be in place for a successful evacuation of a workplace in the event of a fire are: An emergency

plan should be available before the start of each work, A responsible person should be appointed to ensure that fire

precautions are in place, An up to date plan that is appropriate for the circumstances and that makes clear who does

what during a fire, Staff should know what they need to do if there is a fire, Fire drills should be conducted, Fire action


notices should be should be displayed. Fire marshals should be nominated to supervise all fire and the emergency

arrangements. Fire doors and escape routes should be established and clearly marked. Assembly points should be

identified within the work premises for use in the event of evacuation. Exit signs on doors or indicating exit routes

should be provided where they will help people to find a safe escape routes. Escape routes must be well lit.

2) Identify eight common causes of fires in the workplace

Answer:

1) Faulty fuel supplies

2) Faulty appliances and leads

3) Misuse of equipment

4) Chip/fat pans

5) Playing with fire

6) Careless handling of

7) Hot substances

8) Placing articles too close to heat

3) Outline the general role a fire marshal would be expected to undertake in an emergency evacuation of a workplace in

the event of a fire.

The general roles of fire marshal during an emergency evacuation of a workplace in the event of a fire are: He should

check all areas in the building to ensure that an evacuation is in progress and to help where necessary, He should give

special assistance to the disabled and infirm. This may require the use of special evacuation equipments such as an

“evac - chair”. Investigate the site of the fire as indicated by the fire alarm system controls. He will make sure that the

alarm has been sounded and the emergency services notified. He may fight the fire if it is safe to do so. He will make a

roll call, often from the visitor register and staff signing in records, to ensure that everyone has escaped and make a

search of the premises. He can also have a role in the fire risk assessment and inspections to ensure that fire precautions

are being maintained.

4)

a) In relation to the classification of fires give an example of a material that falls within each of the classes A, B, C and D

� Class A – Solid materials – Paper, Wood, Coal and Textiles

� Class B – Flammable Liquids – Petrol, Oil and Solvent

� Class C – Gases – Methane, Propane, Acetylene

� Class F – High temperature fats and oils

b) Identify two method of heat transfer and explain how each method contributes to the spread of fire

The different types of heat transfer methods include: 1) Direct Burning 2) Convection 3) Conduction and 4) Radiation

� Direct Burning: This is the simplest method of fire spread where a flame front moves along or through the

burning material.

� Convection: Hot gases generated from the fire rises straight up and carries the heat along with it

� Conduction: In this case heat may be transmitted through the solid material thus carrying it from one place to

another


� Radiation: Heat energy can be radiated through air in the form of infrared waves which travels in straight lines

and can pass through transparent surfaces.

5) Identify the key components of ‘Fire Triangle’

The key components of fire triangle are: Fuel, Oxygen and Heat

Fuel: Fuel can be a combustible material or substance such as paper, wood, petrol, diesel etc.

Oxygen: Consumed during combustion when it is chemically combined with fuel.

Heat: A heat or ignition source is essential to start the combustion process

6) Outline the factors to consider when carrying out a fire risk assessment of workplace.

1) Construction and use of building: Things to be observed are the type of material used for construction,

what is the fire resistant capacity of the material, are there enough exits for occupants to escape, is the

passage a tunnel type which would cause fast spread of fire etc.

2) Flammable materials: What are the flammable materials kept in the building and calculate the fire load. If

there is no flammable material, then the chance of fire is less.

3) Sources of ignition: Do occupants smoke, what are the other sources of ignition.

4) Work activities generating heat: Do hot work like welding, gas cutting is done in the building.

5) Methods of control: What are the control methods available like, work permit system, NO Smoking

discipline etc.

6) Means of fire detection: Is there Fire alarm, sprinklers etc.

7) Means of raising alarm: Is there siren provided, alarm system provided.

8) Means of fighting fire and maintenance of equipment: Are there fire extinguishers, fire hydrants, are they

adequate.

9) Evacuation routes / protection of evacuation routes: What is the route of evacuation, can all occupants be

evacuated within a short time in that route.

10) Numbers of persons specifically at risk: Who and how many persons are at special risk like pregnant

woman, disable person etc.

11) Fire prevention training / fire drills: Is there a trained team to fight the fire, whether mock drills for

evacuation conducted, is the emergency response plan adequate.

Element 7: Chemical and Biological Health Hazards and Risk Control

1) a) Identify four forms of biological agents

b) Identify three possible routes of entry into the body for a biological agent

c) Outline the control measures to reduce the risk of exposure to a biological agent.

Answer:

(a) The four different types of biological agents may include the following:

� Bacteria: These are single celled micro organisms which normally live both inside and outside the human body.

Some of these are harmless, beneficial and some causes diseases. E.g. Legionnaires disease, Leptospirosis.


� Virus: These are non cellular organisms which normally lives inside the human body and reproduce by hijacking

the living cells to manufacture more viruses

� Fungi: These are multi cellular organisms which usually appear as plants but does not function so as it lives like a

parasite by absorbing the necessary food particles from the host.

(b) The three possible routes of entry of biological agents into human body can be in the following ways.

� Inhalation: Substance can enter the human body through nose and mouth and down into lungs. If the biological

agents are present in the air around the people it may get inhaled.

� Ingestion: Biological agents can enter the human body through the mouth and swallowed down into the

stomach and then moves on through the digestive system.

� Absorption: Biological agents can pass through the skin and into the tissues beneath and then into the blood

stream

� Injection: Biological agents can pass through the skin barrier through damaged skin.

(c) The control measures that can be used to prevent the risk of biological exposures may include the following

� Cleaning / Disinfection: By keeping the work area clean and by washing hands or body with soap or other

disinfection liquids

� Water treatment Programs: Water treatment in the form of boiling, chlorination, reverse osmosis etc. can

be performed on the drinking water

� Vermin Control: Pest control or the control of the nocturnal animals that may spread diseases should be

done.

� Immunization: Immunization can be performed so as to increase the resistance power against specific

infections

� Procedures for handling , containment and proper disposal of biological waste generated within the

workplace

� Health Surveillance: Periodical medical check up to workers who are exposed to biological agents as a part

of their work activities

� Personal Hygiene: Keeping the body clean and washing the hands before having food

� Adequate usage of personal protective equipments like aprons, gloves, masks etc.

� Specific Training: Employees working with biological agents should be provided with specific trainings

related to the hazards, risks and control measures associated with the work activity.

2) An organization uses small quantities of toxic chemicals:

(a) Identify the possible routes of entry of toxic chemicals into the human body

(b) Explain the difference between Acute and Chronic health effects

(c) Identify the sources of information which could be used in the assessment of risk of toxic substances

(d) Outline the control measures that might be required in order to minimize the risk to workers.


Answer:

(a) Toxic chemicals can enter the human body in different ways:

� Inhalation: Chemicals can enter the human body through inhalation. Substances are breathed in through the

nose and mouth and can reach the lungs. Toxic chemicals in the form of gas, mist, fumes or dusts can enter by

this route

� Ingestion: Chemicals can enter the body through mouth and can get swallowed down into stomach and can

finally reach the digestive system. Chemicals in the form of solids, liquids etc. can enter the human body through

this route

� Absorption: Substances passes through the skin and into the tissues beneath and then into the blood stream

� Injection: Chemicals can pass through the skin barrier by physical injection of through damaged skin.

(b)

� Acute Health Effects: Resulting from a single short term exposure to higher levels of substances producing

an immediate effect which is usually reversible e.g. Alcohol affecting the nervous system.

� Chronic Health Effects: Resulting from prolonged or repeated exposure to lower levels of substances

producing a gradual effect that may be unrecognized for a number of years and may be irreversible e.g.

Alcohol causing cirrhosis of the liver.

�

The sources of information which could be used in the assessment of risk of toxic substances may include the

following:

� Product Labels

� EU List of Indicative Limit values

� HSE List of Work place Exposure Limits (U.K)

� ACGIH list of threshold Limit values (US)

� Manufacturers Safety Data Sheets

� The control measures that can be used to reduce the risk of exposure to chemicals will include the following:

� Elimination: If it is possible to eliminate the chemical that is creating the health risk, then that will be the better

option. This can be done by eliminating the process or type of work that requires the use of the substances.

� Substitution / Reduction: If it is not possible to eliminate the hazard try to substitute the hazardous chemical

with a non hazardous one. Changing the physical form of the substances to one that is less harmful e.g. massive

solid rather than powder.

� Isolation: The exposure may be reduced by the use of a substance in an area which is remote to the rest of the

workplace (Isolation by distance). It may be possible to totally enclose the hazardous chemicals inside the

process machinery, storage tanks etc (Enclosure).

� Segregating: Segregating the hazardous substance in the workplace can be done to avoid the risk of exposure by

storing in a segregated storage area and used in an area away from other work processes and personnel’s

� Reducing the duration of exposure: Employees exposure time to hazardous substances should be regulated by

giving rest breaks, job rotations etc.

� Health Surveillance: This may also be required in order to check whether personnel are being affected by

exposure to hazardous substances


� Personal Protective Equipments: PPE should be used in combination with other control measures if adequate

controls cannot be achieved otherwise

� Personal and General environmental hygiene: The personal cleanliness of workers and their general

environment is a very important factor in occupational hygiene control.

(3) Identify the information’s that should be included on a manufacturer’s safety data sheet supplied with a hazardous

substances.

Answer:

The information generally found on safety data sheets includes:

� Information of Chemical

� Identification of substance / preparation

� The manufacturer /supplier

� Composition/information on ingredients

� Physical and chemical properties

� Stability and reactivity

� Toxicological information

� Ecological information

� Hazards

� Hazard identification

� Health effects

� Precautionary Measures

� First aid measures

� Fire fighting measures

� Accident release measures

� Handling and storage

� Transport information

� Exposure controls

� Personal Protective Equipment

� Environment Issues:

� Environmental / disposal considerations

� Disposal considerations

� Others

� Regulatory information

� Other relevant information

4) The construction industry has a high incidence of contact dermatitis.

(a) Identify four substances used in construction that could cause contact dermatitis

(b) Outline the control measures that could be used to reduce the risk of contact dermatitis.


Answer:

(a) The below mentioned substances can cause contact dermatitis: Solvents, clay, plaster, glues, detergents, thinners,

cements, detergents, acids & alkalis etc.

(b) Substitution/change process: Substitute the substance which cause allergic with the one which do not cause allergic

or change the process, Clean working conditions and properly planned work systems: Provide clean working condition,

Give careful attention to skin hygiene principles, Take prompt attention to cuts, abrasions and spillages onto the skin,

Use personal protective equipment, Apply barrier cream which can help, Pre-employment screening for employees who

may have sensitive skin for a substance; if so do not expose him for that work.

5) A factory producing furniture uses wood in the manufacturing process and is concerned about the health risks of

wood dust.

(a) Identify operations which are likely to produce high levels of wood dust in the workplace.

(b) Identify health risks which could be associated with the wood dust.

(c) Outline control measures which could reduce the risk from the wood dust.

Answer:

(a) Activities that are likely to produce high levels of wood dust may include: 1) Machining operations particularly

sawing, routing and turning 2) Sanding by hand and by machine 3) Any operation involving composite boards 4) Using

compressed airlines to blow dust off furniture’s and other articles before spraying 5) The bagging of dust from the dust

extraction system.

(b) The health risk associated with exposure to wood dust may include asthma, cancer etc. Certain types of wood dust

are most likely to cause asthma. Hardwood dusts can cause cancer and therefore can be called as carcinogens. Wood

dust becomes a potential health problem when wooden particles from processes such as sanding and cutting become

airborne. Breathing these particles may cause allergic respiratory symptoms, mucosal and non-allergic respiratory

symptoms and cancer.

(c) The control measures that can be used to reduce the risk of exposure to wood dust may include the following: The

usage of local exhaust ventilation systems in the workplaces to remove the wood dust generated during the work

activity. The usage of vacuuming to clean up dust can also be considered as an option to remove the suspended dust

particles. Dust generated in the workplace can be suppressed by water jet or spray. Periodical medical check up need to

be conducted for the employees (Health surveillance) who are regularly exposed to wood dust, Usage of adequate

respiratory protective equipments.

6) a) Identify two forms of hazardous substances

b) Outline the personal hygiene controls to be followed to reduce the risk of ingestion of hazardous substances

Answer:

(a) Solids: A solid block of material. Substance having a definite shape and volume under normal temperature and

pressure.

Liquid: A basic state of matter. Substances having a definite volume but no definite shape under normal temperature

and pressure


Gas: A basic state of matter. Substances having neither shape nor volume under normal temperature and pressure.

Dust: Tiny solid particles dispersed in air and these are normally generated by activities like grinding, polishing, milling,

blasting etc.

(b)

7. (a) Identify two types of asbestos to which workers in the construction industry may be exposed

(b) Give examples of where workers might find asbestos while undertaking maintenance or refurbishment work on a

building

Answers:

(a) Some of the types of asbestos to which workers may be exposed may include:

Crocidolite or Blue asbestos

Chrystolite or White asbestos

Amosite or Brown asbestos

(b) Examples of where asbestos is likely to be encountered during renovation work of a building may include; pipe

lagging, asbestos cement products such as roofing sheets, loose asbestos packing used as fire breaks in the ceilings

voids, sprayed asbestos coatings on steel members to provide an element of fire resistance, asbestos wool used as wall

insulations, asbestos rope, gasket on boilers and coolers, certain textured coatings or decorative plasters.

7. A recent increase in work related ill health has been noticed amongst the 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’

(b) Give possible reasons for the increase in work related ill health amongst the workers.

Answer.

(a) Workplace Exposure Limit is defined as the maximum concentrations of airborne contaminants, normally measured

across a particular reference period of time to which employees may be exposed.

8. Ammonia has been released into the atmosphere of a workplace.

(a) Outline the typical health effects resulting from exposure to ammonia

(b) Give the meaning of the term acute” heath effects”

(c) Identify suitable air monitoring methods for ammonia.


Answers:

(a) Typical health effects resulting from exposure to ammonia may include irritation and possibly burning of the

respiratory system, pulmonary oedema, coughing and sneezing, eye irritation together with running eyes and nose,

irritation and burning to the skin.

(b) Acute health effects means effects resulting from a single short term exposure producing an immediate effect which

is usually reversible e.g. Alcohol effecting the nervous system.

(c) Presence of ammonia in the atmosphere can be easily detected by anyone of the following air monitoring methods:

Stain tube detectors – Stain tube detectors provide a very convenient method of analyzing ammonia contamination of

the workplace air.

Passive sampling

Active sampling

Electrochemical detection device such as pulsed amplified detectors

9. (a) Give the meaning of:

(*) “Hazardous waste”

(*) “Non- hazardous waste “

(b) Outline the key design features of a permanent spill protected / bunded area in order to protect against accidental

releases and pollution.

Answer:

(a) (*) Hazardous wastes are those which is harmful and / or dangerous to health and the environment which on

disposal get decomposed and results in the formation of harmful products.

(*) Non hazardous wastes are those which is not harmful either to the health or the environment and does not

decompose and result in the formation of harmful products.

(b) Bunds around the tankages are provided to protect against the accidental releases and the pollution cause by the

chemicals or the flammables. A good structured bund should be always located on a stable ground and at suitable

distance from the water courses without connections either to the drain or sewer. It should be provided with a concrete

slab base and walls with the surface of both being impervious. There should be adequate space between the containers

and the bund walls and the bunded area should have a capacity of 110% of the total capacity of the containers. The

bunded area should have proper protection against the temperature and the climatic conditions (weather proof) and

also against the damage from the possibility them being struck by passing plants and vehicles. Bunds should be provided

with proper provisions for emptying the spills in case of accidental releases and with proper monitoring systems.

10. A company produces a range of solid and liquid wastes, hazardous and non - hazardous. Outline the arrangements

that should be in place to ensure the safe storage of the wastes prior to their collection and disposal.

Answer:

In answering this question, candidates can refer to arrangements such as:

The completion of risk assessments that address the nature, properties and quantities of the wastes likely to be stored,

Minimizing the quantities stored by organizing regular collections, Ensuring the separation of incompatible wastes

Providing appropriate means for containing the wastes in secure storage facilities (e g protected against unauthorized

persons, weather, vehicles, etc), Installing and maintaining fire protection and fire-fighting systems in the case of


Flammable or combustible wastes, Installing bunds and drawing up procedures to deal with slippages that might preset

environmental risks, Providing safe means of transport and access to the storage site, Ensuring that wastes are

accurately identified and that warning signs are in place where appropriate, Training employees in the precautions to be

taken, Ensuring that they are provided with, and use, appropriate personal protective equipment, such as gloves,

overalls and eye protection.

11. A worker is engaged in general cleaning activities in a large veterinary practice.

(a) Identify FOUR specific types of hazard that the cleaner might face when undertaking the cleaning.

(b) Outline the precautions that could to taken to minimize the risk of harm from these hazards.

(a) Hazards that specifically associated to cleaners are:

� Cleaning fluids

� Manual handling

� Slips/trips/falls

� Presence of sharp objects / projections can cause penetration hazards

� Those associated with the working environment, such as biological hazards, contact with animals and those

arising from the use of specialized equipment.

(b) In answering part (ii), Examiners are looking to candidates to outline precautions such as:

The provision and use of personal protective equipment (including overalls and gloves), The introduction of a procedure

for the handling and disposal of sharps, The need for animals to be kept in secure enclosures, The possible need for

immunization against diseases known to be transmitted by animals, Highlighting that the worker would need specific

training in the precautions outlined will gain an additional mark.

12.

a) Identify four forms of hazardous substance for which respiratory protective equipment could be used to reduce the

risk of harm

b) Outline factors that could reduce the effectiveness of the respiratory protective equipment.

13. Outline the limitations of Exposure Limits

Occupational exposure limits are a useful guide but there are a number of limitations such as: Toxicology is an imprecise

science and the data used could be incorrect: Apart from breathing in the substance there are other routes on entry for

hazardous substances which are not covered: The actual doses received by workers may vary enormously: The

measurement of the actual amounts in the air could be inaccurate

14.

(a) Identify four forms of hazardous substance for which respiratory protective equipment could be used to reduce the

risk of harm

(b) Outline the factors that could reduce the effectiveness of the respiratory protective equipment.


Element 8: Physical and Psychological Health Hazards and Risk Control

1) a) Outline the possible health effects from exposure to high levels of noise

b) Give two examples of noise control techniques, other than personal hearing protection, that would benefit all works.

c) Outline the factors that are likely to affect the performance of personal hearing protection

Answer:

(a) The possible health effects due to exposure to high levels of noise can be in the form of Acute, Chronic and other

health effects

Acute Health Effects: Health effects due to short term exposure to high levels of noise can be Trauma, Temporary

Threshold Shift, and Short term tinnitus.

Chronic Health Effects: Health effects due to long term exposure to noise can be Tinnitus, Permanent Threshold Shift

and Loss of Frequency

Other Health Effects: Sleeping disturbances, Cardio – Vascular Trouble, Annoyance, Irritations

(b) Enclosure / Insulation: Enclosing the noise source is clearly the most effective means of noise control in the open

Isolation: Isolation involves separating the machines from any supporting structures using vibration

absorbent mats or springs

Absorption: Absorption involves putting sound absorbing materials in the workplace to absorb these sound

waves before they can reach the receiver

(c) The following factors are likely to affect the performance of personal hearing protection:

� Lack of Maintenance: Lack of proper maintenance of the personal hearing protection may reduce the

effectiveness of its intended use

� Poor Quality / Non Compliance to standards

� Incompatible with other personal protective equipments

� Ergonomic Issues

2) In relation to the ill-health effects from the use of vibrating hand-held tools:

(a) Identify the typical symptoms that might be shown by affected individuals.

(b)Outline the control measures that may be used to minimize the risk of such effects.

Answer:

In answering part (a) of the question, Examiners expected candidates to identify symptoms such as numbness and

blanching of the fingers and swollen and painful joints in addition to a reduction in dexterity, strength and sensory

perception.

(a) The symptoms that can be seen on the individuals exposed to vibration will include the following:

Tingling and numbness in the fingers, not being able to feel things properly, Loss of strength in the hands;

White finger, Back pain, Reduction in sense of touch and temperature, possibly permanent numbness or tingling in your

fingers, Damage to muscles, bones and joints


For part (b), candidates should have outlined a hierarchy of control measures such as: elimination by mechanization or

automation; substituting the tools with lower vibration producing equipment; reducing the time of vibration exposure to

the operatives; introducing a planned maintenance programme for the tools and providing appropriate personal

protective equipment such as gloves to keep hands warm.

3) (a) Identify FOUR types of ionizing radiation

(b) Outline the main principles of control for ionizing radiation

Answers:

(a) Four different type of ionizing radiations are:

Alpha: They are sub atomic particles emitted by some radioactive materials. These do not have much penetrating

power and can be easily stopped by thin materials such as paper

Beta: These are also sub atomic particles emitted by some radioactive materials. They have more penetrating power

and can easily penetrate through the skin into living tissues

Gamma: A form of high energy electromagnetic radiation emitted by some radioactive substances. They have high

penetrating power and can shine right through rigid objects like steel and concrete

X-Rays: A form of high energy electromagnetic radiation emitted by some radioactive substances. They have high

penetrating power and can shine right through the human body

(c) By reducing the time of exposure to the ionizing radiation, maintaining a safe distance between the source of

radiation and the workers, providing barriers such as lead, concrete or water will give good protection from penetrating

radiations such as gamma rays. Workers should be given specialized training with respect to the hazards and preventive

measures of radiation and all the works involving radiation should be carried out under strict supervision. The leftover

radiation materials should be disposed off in a responsible manner. Proper monitoring of the exposed personals and

also the environment should be carried out to ensure that the emitted radiations are within the safe limits.

4) (a) Identify two types of non ionizing radiations and give an occupational source of each.

(b) Outline the health effects associated with exposure to non ionizing radiations

Answer:

(a) The two types of non ionizing radiations can be selected from the following list of radiations:

Ultra violet rays – UV rays: Ultra violet rays can be raised from welding operations or excessive exposure to sun

Infra red rays – IR rays: rays emitted during the gas cutting operations, glass manufacturing areas, red hot steel in

rolling mills

Lasers – lasers shall be emitted from the laser equipments,

Microwave – rays generated from the microwaves, radar and telecommunication equipments

(b) Non ionizing radiations can have bad effects on the health. Exposure of the eyes to the ultra violet radiations can

damage the cornea and produce pain and symptoms similar to that of sand in the eye. The effects on the skin ranges


from redness, burning, accelerated ageing to various types of skin cancer. Infrared rays can cause cataract in the eyes

High power lasers can cause serious damage to the eyes as well as producing skin burns. Short term adverse effect of

electromagnetic rays may include electric burns and shock. Chronic exposure to UV rays can accelerate ageing and

increase the risk of skin cancer. Microwaves can be absorbed and can cause internal heating of the skin, high doses can

cause internal organ damage and could be fatal.

5) A noise survey has been conducted in a factory which has resulted in the need for provision of hearing protection

Outline the advantages and disadvantages of:

(a) Ear muffs

(b) Ear plugs

Answer:

(a) Advantages of ear muffs are; gives a complete protection to the ears and a good reduction of all sound frequencies,

designed in such a way that one size fits for most head sizes, easily seen at a distance to assist in the monitoring of their

use, less attenuation variability among the users, they can be integrated with other personal protective equipment such

as a hard hat, they are reusable and have a low risk of infection

Disadvantages of ear muffs are; inconvenient to use with other personal protective equipments and their reliability

might be affected by the presence of long hairs, glasses or ear rings, uncomfortable to use in hot and humid work areas,

inconvenient to use in confined work areas, less portable and heavier when compared to ear plugs

(b) Advantages of plugs are; small and easily carried, convenient to use with other personal protective equipments,

more comfortable for long term wear in hot, humid work areas, confined for use in confined work areas. Ear plugs are

available in a range of designs and types that are disposable and thus do not need to be stored after use.

Disadvantages of ear plugs are; requires more time to fit, more difficult to insert and remove, require good hygiene

practices, may irritate the ear canal, difficult to see and monitor the usage, their effectiveness decrease with usage.

6) Outline the factors that may lead to unacceptable levels of occupational stress amongst workers.

Answer:

Stress is the adverse reaction people to excessive pressures or other types of demand placed on them. It arises when

they feel that they can’t cope. Occupational stress can rise among the workers due to the following reasons.1) The

culture of the workplace including, whether or not there is a blame culture or working excessive hours. 2) The demands

of the job – Whether the work is boring or repetitive type, the amount of training required and the amount of the work

3) The amount of control the worker has over their work 4) Relationships among the workers can give rise to stress

especially when the relationship are poor or involve bullying or harassment 5) Changes and fears about the job security

can lead to stress 6) Confusion about the employees role and what their objectives are 7) Lack of support from the

management can increase the employees stress level. 8) Workplace environmental factors like inadequate lighting,

cramped/ dirty or untidy conditions, poor layout, inadequate ventilation, presence of noise and vibrations etc.

Documents

NEBOSH – IGC 2 QUESTION BANK