Element 1:
Workplace Hazards and Risk Control
Excavation – Hazards and Control Measures:
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.
•
Oxygen Deficiency: Deficiency of oxygen may happen due to the depth of excavation / Trench
•
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
•
Biological Hazards
•
No proper access/ egress
•
Mobile equipments falling into the pit
•
Inadequate illumination
Precautionary Measures:
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
discovered by careful digging with hand. Before performing the mechanical excavation, underground
utilities should be isolated if possible. The perimeter of the excavation should be protected by means
of hard barricades, 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 periodically monitored by
means of detectors to detect the presence of toxic gases as well the availability of oxygen. If the
presence of toxic gases is identified it should be removed by providing adequate ventilation or supply
the workers with adequate respiratory protections. Accumulated water inside the excavation / trench
should be removed by providing adequate dewatering systems (pumps & motors) and protected against
the runaway water (Spoils). Adjacent structures near to the excavation should be protected by
providing adequate physical support or underpinning to the structure. Proper lighting and caution
boards should be provided in and around the excavation area. Ladders should be provided for the
movement of workers into and out of the excavation correspondingly ramps should be provided for the
movement of vehicles. 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 before the start of work, accidental fall of materials and after any
undesired or unexpected events. Vehicles should be prevented from approaching the excavation side by
use of barriers and signage’s. Employees working in excavation should be provided with adequate
personal protective equipment’s. Periodical inspection should be performed before, during and after
excavation.
Mobile Scaffold (Mobile Tower Scaffold):
Hazards:
•
•
•
•
•
•
Falling of personnel from the working platform
Objects falling from the platform or due to the work activity
Collapse of the structure due to overloading, inadequate construction, inadequate bracings, lack
of maintenance etc.
Overturning of the structure (moving the structure through uneven surfaces, overloading at
edges, broken castor wheels, moving with personnel on top etc.)
Contact with overhead electrical line
Collision with the obstructions or vehicles
Precautions:
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 overheads when the tower is moved
Outriggers should be used where necessary to ensure stability
Mobile tower should be built by trained workers
Tower platforms should be fully decked
Castor wheels should have adequate strength
The mobile scaffold in use shall rest upon a suitable footing and shall stand plumb
All wheels shall be provided with a positive locking device to hold the scaffold in position
Demolition:
Hazards:
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, buildup 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
Site Security for Children:
Some of the security measures 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
Mobile Elevated Working Platform (MEWP)
Precautionary Measures:
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.
Violence
Works that has the proximity for violence at work:
Handling money or valuables - cashiers,
Providing care, advice, education and training (nurses, ambulance staff, social workers,
teachers)
Carrying out inspection or enforcement duties (police and traffic wardens, ticket inspectors)
Working with mentally disturbed, drunk or potentially violent people (prison, officers, bar
staff, mental health workers)
Working alone (home visitors, taxi drivers, and domestic repair workers)
Control Strategies:
Zero tolerance policy and prosecution to offenders, 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, Panic alarms, Visitors should not be allowed after dark, secure parking areas for
the staff.
Movement of People – Slips & Trips
Factors that may cause slips & Trips:
Floor Surface: Slippery floor, holes on the floor, uneven floor, smooth floor
Contamination: Spillages, Leaks
Obstructions: Rubbish, trailing cables, rugs etc.
The Task: How the task is performed: Carrying loads that is not properly arranged, Overloading,
obstruction of vision etc.
Environment: Inadequate lighting, dusty atmosphere etc.
Footwear: Unsuitable footwear
The People: Unaware of the dangers
Precautionary Measures:
Risk Assessment: Conduct a risk assessment on the path, which is used by the employees for
movement to identify the hazards and to provide the control measures.
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, adequate ventilation if possible to
remove the dust or smoke persisting in the workplace
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
Independent Tied Scaffold:
Precautionary Measures:
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
Heat Stress:
Effects of Heat on Workers:
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.
Precautionary Measures:
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 equipment’s 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.
Working on Height – Fragile Roofs / Roofs (Can be asked in both ways, control
measures will be almost same in both)
Hazards – Fragile Roofs
Fall from roof edges
Fall through fragile roof sheet.
Fall through openings in the roof
Hot Bitumen (Coal tar) material when using it.
Material Fall from height
Control Measures:
1)
2)
3)
4)
5)
Provide edge protection around the roof perimeter
Cover or guard the openings on the roof
Use crawler board on slope fragile roof
Provide proper access and egress to the roof
Tie safety net below the roof
Protections for preventing material fall from height:
1)
2)
3)
4)
Materials shall be lowered from height, no material shall be dropped.
Do not keep any loose materials unsecured on the roof
Tie the tools used for roof work to the waist
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)
2)
3)
4)
Employees send for the roof work should be selected and trained
Employees selected for the job should undergo premedical test.
Establish Height work permit
Appropriate rest pause should be introduced.
ELEMENT -2
GC-2 -TRANSPORTATION HAZARDS AND RISK CONTROLS
1) Describe the physical features of traffic routes within the workplace designed to
ensure the safe movement of vehicles and safety of employees.-8 Marks
Traffic routes should be separated by using hard barrication and to be separated from
vehicles whenever possible reducing the need to reverse by using one way systems
.traffic routes should be free from steep gradients and overhead cables ,should be firm
ground and minimising sharp and blind corners .specified with parking areas for
vehicles .Speed limit to be controlled and warning signs should be displayed ,The area
has to be provided with well illuminated and maintaining good housekeeping . The
traffic routes should be provided with drainage system, zebra crossing points for people
and banks men should be appointed in some areas where signals are not provided.
Emergency parking areas are to be established, free from slippery and poth holes.
2) Outline the factors that should be taken into account when planning traffic
routes for internal transport - 6 Marks
Factors are to be considered when planning a traffic routes for internal transport foe a
safe operation of vehicle movement and pedestrian movement. Type of vehicles , size
and length , consider it should suitable for the environment condition , which type of
goods are planning to handle , is it hazardous such as liquid, solid or gas , is the work is
going to carry out in the night, So consider illumination level , the route should be
sufficient width and free from slippery , Environment conditions are to be consider like
rain ,snow and temperature etc... Drainage conditions, other factors such as number of
people working, pedestrian routes and the work activities carried out, Location wise.
3) Outline control measures are to be taken to prevent accidents when
pedestrians are required to work in vehicle manoeuvring areas - 8 Marks
Divert the vehicles by providing signage’s and Barricade the area and Sign board’s
provision and the workers should have Reflective jackets .Reduce the speed by
implementing speed control system or providing humps. Banks man for controlling the
traffic, Awareness training delivered to all people and crossing points should be
controlled either by signals. The area has to be well lit and pedestrian walkways to be
constructed.
4) Outline the control measures by which the risk of accidents from reversing
vehicles within a workplace can be reduced -6 marks
Installing a one way traffic system to minimise the need for reversing, segregating
vehicles and pedestrians, including separate access and egress and providing clearly
marked crossing places, fit reversing alarms to alert to detection device to warn the
driver of an obstruction, or automatically, Flashing beacons should fitted with the
vehicles, the vehicle should have adequate mirrors and convex mirrors are to fixed.
5) The ware house of a ceramic tile manufacturer is to be developed to increase its
storage capacity and to enable the use of internal transport to transfer the goods to and
from the loading bays.
a) Outline the design features of the traffic routes that should be addressed in order to
minimise the risk of forklift truck related accidents.-6marks
b) Describe additional measures that need to be taken to protect pedestrians from the
risk of being struck by a fork lift truck in the ware house.-6 marks
a) The design feature should be addressed such as providing traffic routes with smooth and
suitable surfaces and with the right width and headroom for types of vehicles that will use
them, eliminating sharp bends, blind corners and steep gradients and siting convex mirrors on
those corners that are unavoidably blind ,installing one way system ,to minimise the need for
reversing , the traffic routes for forklift should be clearly marked-yellow lines .introducing
speed limits and providing speed retarders, the provision of good standard lighting, the traffic
route designed by separating pedestrians and clearly marked crossing points .Procedural
design features like selecting and training competent drivers .
b) Separate the forklift truck and pedestrians by implementing barricades, implement one way
traffic system. The traffic route area provided with Sign boards and the workers should
have high visibility clothes .Reduce the speed by implementing speed control system or
providing humps. Banks man for controlling the traffic, Awareness training delivered to
all people and crossing points or controlled either by signals. The area has to be well lit
and pedestrian walkways to be constructed. For the warning of people forklift trucks
should be provided with flashing beacons and reverse alarm.
10) Identify eight health and safety hazards relevant to the role of a long distance
delivery driver.
 Safety Hazards:- Loss of Control & Overturning ,it may happen due to lose control of
their vehicle for various reasons such as Driver Error, bad Environmental
Conditions such as snow fall , slippery road and sharp bends, lack of proper grip and
Mechanical Failure such as break failure , engine failure . another hazards like
Collision can occur between the vehicle and Other Vehicles,Pedestrians ,Fixed
structures
 Health Hazards:- Long distance driving increases the stress and fatigue , other
hazards like work related upper limb disorders and whole body vibration ,these
hazards increase the blood pressure and other diseases, lack of sleeping increase
mental strain and lead to lack of concentration.
11) outline the factors to consider when assessing the risks to long distance
driver -8 marks
Competency of the driver, The distance to be travelled and driving hours, rest hours
and availability of refreshing areas, the type of load (hazardous Materials) and the value
of the goods, The medical condition such as fitness, Eye sight, The journey should be
analyzed, the type of road condition and the route (Isolated places to be travelled by
alone) environment condition, vehicle condition is suitable for the intended purpose,
suitable for the environment, Inspection and maintenance.
12) Outline the possible causes of a dumper truck overturn on a construction site
-4 marks
Driver error may lead to toppling and overturning, riding the vehicle with high speed
and operating the vehicle in sharp corners with high speed. Overloading of vehicle and
road conditions such as slippery, slopes and unstable road, Mechanical failure such as
break failure or engine failure of coupling system, in flatten tires.
13) Outline the control measures to reduce the risk associated with workplace
transport operation -8 Marks
 The Workplace Environment:- should be designed such as Vehicle Free Zones or
Pedestrian Free Zones.proper Vehicle Traffic Route Layout, Segregation of
Vehicles and Pedestrians by providing proper barrication, crossing point may be
implemented for people and Adequate Lighting, Appropriate Signage should be
installed. In the traffic route Gradients should be avoided and while designing
avoid Blind spots and Good visibility for the operator should be ensured. In rush
vehicle movement area banks men shall be used.Speed limits should be set for
traffic routes.
 The vehicle: - Suitable for intended use and Suitable for the environment such as
per the environment condition and based on the goods transported .Maintained
in safe working order and Inspected routinely before usage.Competent driver
should be appointed.
 The Driver: - should have license and Competent to drive the vehicle, medically
fit to drive, provided with specific information, instruction and training and
adequate supervision.
14) Identify four ways in which people can be injured by vehicles in the
workplace.-4 Marks
15) Identify issues that should be included in a training programme for vehicle
drivers in order to reduce the risk of accidents to themselves and other
employees-6 marks
Element 3:
Musculoskeletal Hazards and Risk Control
Manual Handling:
Manual Handling Injuries:
Muscular sprains and strains
Back Injuries
Trapped nerve
Hernia
Work Related Upper Limb Disorder
Cuts, Bruises and Abrasions
Fractures
Ergonomic Assessment of Manual Handling (TILE)
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 in nature
Does the task involve lifting the load through a vertical distance
Rest breaks provided while performing the task
The distance that need to be covered while performing the activity need to be considered
Does the task involve lifting the load above the shoulder height
At what height does the load need to be picked up, carried or put down
The factors that need to be considered with respect to Individual while performing a manual handling
includes:
Gender of the individual performing the task
Physical strength of the individual
Stature - Physique, Height, Weight etc. need to be considered
Health or Medical condition of the person performing the task
Level of training received by the individual
Person’s perception of their ability
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
The factors that need to be considered with respect to load while performing a manual handling
includes:
Path of travel
Level variations on path
Hot/cold/humid conditions persisting inside the workplace
Amount of illuminations provided inside the workplace
Working space available for the employees to perform the task
Forklift Trucks:
Hazards:
Tipping over
Pedestrians being struck
Hit by falling objects
Operators falling
Collisions
Control Measures to avoid the risk of collision of forklift with workers:
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: Speed limits for the forklifts should be established where ever necessary
8) Adequate lighting: Adequate lighting should be ensured in the forklift maneuvering areas
Battery Operated Forklift Trucks:
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
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.
Cranes
Hazards / Risks associated with cranes:
1) Overturning – Overloading of crane, attempt to lift a load to an excessive radius, unstable
ground surfaces / inadequate supporting surfaces, operation under extreme wind condition
2) Collisions – Collision of crane parts with an adjacent crane, with fixed / temporary structures,
with overhead electric power lines
3) Failure of Support – Failure of outriggers
4) Loss of Load – Non availability of safety latches, breakage of slings attached to the load,
breakage of wire ropes
5) High Winds – Presence of heavy winds can cause crane to overturn, slippage of loads etc.
Precautions while using a crane:
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
Precautions while performing lifting operations 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.
Conveyors:
Hazards:
The main hazards associated with the conveyors are:
1) In running nip points where fingers might be drawn into the moving parts
2) Entanglement: Where loose clothing might become entangled with the rotating parts
3) Falling objects from overhead conveyor systems
Control Measures:
1)
2)
3)
4)
5)
6)
7)
8)
Warning signs or sirens to alert people that the belt is about to start moving
Guarding of moving parts to prevent drawing in and entanglement
Emergency stop buttons should be available
Barriers should be installed to exclude people fro the conveyor area
Information, instructions and training for the operators
Controlling of loose clothing and long hairs
Periodical maintenance and inspection of the conveyor
Operators should be provided with adequate personal protective equipments
Display Screen Equipments (DSE) – Laptops, Computer etc.
Health Risks Associated with the use of DSE
Musculoskeletal Disorder or WRULD: Which normally occurs as a result of repetitive use of
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
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
Ergonomic assessment of a display screen equipment workstation:
1) Provide adequate lighting
2) Avoid glare or reflections from the screen
3) Comfortable room temperature
4) Adequate working space should be ensured
5) The Chair must be of the swivel type and have four 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) 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 adjusted as per individual
requirements.
7) Document holder should be stable, adjustable in height and angle and be placed close to
the screen to minimize head movement.
8) 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
9) 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.
10) 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.
Work Related Upper Limb Disorders (WRULD):
•
Work related Upper Limb Disorders (WRULD) do not happen as a result of a single
accident or injury. Rather, they develop gradually as a result of repeated trauma.
Factors causing WRULD:
Task Factors - Repetitive motion, Awkward posture, Forceful movement, Lack of
recovery time, Long periods of repetitive activity
Environmental Factors – Temperature, Lighting, Humidity, Noise, Vibration
Equipment Factors – Equipment Design, Equipment Adjustability
WRULD – Control Measures:
Mechanization – Replacing manual handling with machines or equipment’s
Job Rotation – Allowing the employees to work in shifts thereby reducing the duration of
exposure
Job Enlargement and Enrichment - A job design technique in which the number
of tasks associated with a job is increased (and appropriate training provided) to add greater
variety to activities, thus reducing monotony
Team Work – Involving more employees to perform a task
Workplace Design – Ergonomic design of workplace environment will help to reduce the stress
and fatigue generated from the work activity
Tools and Equipment Design – Ergonomic design of equipment’s or machines used to perform
an activity will help to reduce the risk factors causing WRULD
Work Practices – Modification in the pattern by which the work is performed
Regular Breaks – Periodical breaks in between the work will provide sufficient recovery time for
the muscles working under stress
Training – Employees should be informed about the factors causing WRULD (in association with
the work) and also about the precautionary measures to be taken to avoid the health risks
Medical Surveillance – Periodical health checkup of the employees should be performed to
identify the symptoms that may create health risks
Element 4:
Work Equipment Hazards and Risk Control
Hazardous Mechanical Motions / Actions:
1)
2)
3)
4)
5)
6)
7)
Rotating Motions
Reciprocating Motions
Transverse Motions
Cutting Action
Punching Action
Bending Action
Shearing Action
Mechanical Risks:
Entanglement: When the body parts get caught on the rotating parts of the machinery and the person
may be drawn into the machine
Traps: A part of the body is caught between two moving parts of the machine and drawn in. Traps
usually happens at the nip points
Impacts: Impact happens when the body is struck by the powered part of a machine. This happens in
reciprocating machines, during the back-and- forth or up-and-down motion of a machine.
Ejections: Impact, stabbing or puncture injuries caused by flying objects or the machine parts detached
from the machine
Crushing: Crushing: Crushing happens when the body is trapped between two moving parts or one
moving and a fixed object
Shearing: Shearing happens when the body parts are trapped between two parts of the machine, one
moving past the other with some speed.
Cutting: Cutting results when the body part comes in contact with the sharp edge of the machine parts.
Non – Mechanical Hazards:
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
Safe Guards and Safe Guarding Devices:
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:
1) Fixed Guards – These types of guards shall be fixed to the machine and act as a physical barrier
between the worker and the rotating parts of the machine. The position of these types of guards
cannot be adjusted.
2) Adjustable Guards – The position of these types of guards can be adjusted as per the needs of the
operator or the work requirements
3) Self-adjusting guards – The position of these types of guards will be automatically adjusted by the
machine as the work requirements.
4) 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:
1) Presence sensing devices – The photo electric presence sensing device uses a system of light
sources and controls which can interrupt the machines operating cycle:
2) Pullback devices – Pull back device utilizes a series of cables attached to the operator’s hands,
wrists and arms, which pulls back the arm of the operator during the machine cycle, thus
preventing the hand from coming in the danger zone during the machine operation.
3) Restraints: The restraint (holdout) device utilizes cables or straps that are attached to the
operator's hands and a fixed point. Here the length of the cables shall be restricted thus preventing
hand of the operator from coming in the danger zone.
4) 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.
Pedestal Drill - Hazards & Precautions:
The 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 8) Impact from the work piece if the bit
jams and the work piece rotates 8) Electricity used for the operation can cause electrocution
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 by using adequate
personal protective equipments, routine maintenance including inspection and portable appliance
testing, Using trained and competent operators. Operators working on the pedestal drills should be
thoroughly informed, instructed about the risks associated with the work, his work should also be
supervised by a competent person.
Cement Mixer - Hazards & Precautions:
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
Precautionary Measures: 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.
Petrol Driven Chainsaw - Hazards & Precautions:
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. :
Precautionary Measures:
Fixed enclosing machine guards
Usage should be restricted to competent and trained operators
Partial side guards should be used
Periodical inspection should be carried out
Adequate maintenance of the equipment
Job rotation can be implemented to avoid the workers exposure to vibration
Refueling of the fuel should only be carried out in well ventilated area
Operators should be provided with adequate personal protective equipments like face shield,
gloves, ear muffs etc.
Bench Mounted Circular Saw - Hazards & Precautions:
Hazards:
Cutting on contact with the blade
Entanglement with the drive motor
Drawing in at nip points between motor and driver belt
Ejection of work piece during cutting
Electricity
Noise
Health hazards from inhalation of wood dust
Precautionary Measures:
Machine guards in the form of fixed guard / adjustable guards should be provided
Adequate ventilations should be provided to remove the dust generated during the work
activities
Routine inspection shall be performed on the equipment
Regular maintenance
Competent operators should be assigned to do the task
Operators should be provided with adequate personal protective equipments
Hand Tools – Precautionary Measures:
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. Do not use hand tools like wrenches when their jaws
are sprung. Hand tools whose head has been mushroomed or with blunt surface should be taken out of
service or should be take for adequate maintenance. Tools with loose, cracked, splintered or taped
handled should not be used for the work activities. Employees working with the hand tools should be
provided with adequate personal protective equipments. Users should be given appropriate
information, instruction and training. Tools should be maintained in a safe condition. Good supervision
should be ensured.
Power Tools – Precautionary Measures:
Power tools should be carefully selected to ensure that it is suitable for the task and for the
environment in which the task need to be performed: The safe guards or safe guarding devices
associated with the power tools should always be used while performing a task: Power tools should be
routinely inspected by the operator or by a competent person before using it: Maintenance of the tools
should be carried out periodically to ensure the smooth operation of the parts: The tools and the parts
of the equipment should only be used within their design considerations: Cables along with the
equipment should be properly managed to avoid tripping of other personnel or near by workers:
Employees working with the power tools should be provided with adequate personal protective
equipments that protect them from hazards involving noise, vibration, dust etc. Operators using the
power tools should be trained and given information on the safe use of the tool:
ELECTRICAL SAFETY: - ELEMENT -5
1) With reference to an electric circuit ,State the relationship between voltage , Current and
resistance -6 Marks
Volt: The unit of measurement of electrical potential
Ampere (Current): The unit of measurement of electric current flow
Ohm (Resistance): The unit of measurement of electrical resistance
Relationship of Volt (V), Current (I) & Resistance (R)
As per Ohm’s Law: V = IR or I = V/R
2) Outline the factors that could be affecting the severity of injury from an electric shock
received from a defective hand –held tool.-6 Marks
or
Outline four factors that may affect the severity of injury from contact with electricity
-6 Marks
Voltage: -Higher voltages enable the current to pass with ease through materials
with higher resistance.
Current: -The larger the current, in milli-amps mA, the greater the likelihood of
injury
Time: -The longer the body is exposed to an electric shock the higher the chances of
heart fibrillating. The duration of exposure is measured in mill- seconds
Conductivity or resistance: -of the body and surroundings. E.g. sweating lowers
skin resistance:
Current path:- The most dangerous routes that current can take through the body
are across the chest.
3) Outline the dangers associated with electricity -8 Marks
Dangers associated with electricity are electrocution , burns, arcing, fire and
explosion
Electrical Shock:- Electric shock is the convulsive reaction by the human body to the
flow of electric current through it. Most incidents of electric shock occur when the
person becomes the route to earth for alive conductor
Electrical Burns :- Burns of the skin occur at the point of electrical contact due to the
high resistance of skin, These burns may be deep .burns may also occur inside the body
along the path of electric current
Electrical Arcing:- Conductor carries sufficient potential to jump across an insulation
material arcing occurs .The main cause is unsafe working practices and working to close
too high voltage conductors . Electrical arcing lead to indirect burns and injuries to eyes
.
Static Electricity :- The main hazard of static electricity is the creation of sparks in an
explosive or flammable atmosphere. The generation of static can be caused by the rapid
separation of highly insulated materials by friction .it may lead to explosion and fire .The
buildup of electrons on weak electrical conductors or insulating materials
Fire & explosions caused by Electricity:-Electrical fires are caused by a lack of
reasonable care in the maintenance and use of electrical installation and equipment.
Overheating of cables and equipment will occur if
become overloaded ,loose
connections bunching of cables together can lead to fire. If explosive atmosphere is
present and any short circuits and sparks will increase the explosion.
4) Outline the emergency action to be take if a person suffers a severe electric shock.-6
Marks
The emergency action to be taken in case of any severe shock such as Don't touch the
victim raise the alarm by calling help from colleagues, Unplug or turn off the power,If you
can't turn off the power, use a piece of wood or a broom handle to separate the victim from
the power source. Call for emergency and ambulance . Check breathing ,If breathing place in
recovery position& If not breathing apply CPR >in case of any burns shift the person into
well ventilated area and maintain the body temperature .Never give water for electrocuted
person .
4) Outline the effects of human body from a severe electric shock -6 Marks
Health effect of human body from severe shock depends on the amount current , voltage,
duration and environmental conditions etc..these situations may lead to number of health
effects on human body such as Damage to nervous system ,if the chest in the current path
respiratory movement could be prevented
causing
asphyxia Irregular heartbeat
(fibrillation) External & Internal burns occur at the point of electrical contact due to the
high resistance of skin .Muscular contractions & Physical trauma ,Stopping breathing
(respiratory paralysis)
Such health effects may be so severe that they ultimately result in death. They may also
result in secondary effects such as being thrown off a ladder.
6) Describe how earthing can reduce the risk of receiving an electric shock-4Marks
Good and effective earthing absolutely essential and must be connected .To reduce the
risk receiving the shock from electrical equipment use good conductive material with less
resistance ex:- copper. Maintain earth pit with zero resistance , The earth cable joint should
free from loose connections. To avoid the shock from the earthing, cable should be covered
with sleeve ,The earth pit should be filled with coal, salt and sand ,Continuity of the earthing
to be maintained for that there should be single earth strip or copper cable. using of Earth
leakage circuit breakers will give adequate protection
7) In relation to the use of electrical cables and plugs in the work place :a) Identify four examples of faults and bad practices that could contribute to electrical
accidents.-6 Marks
b) Outline the corresponding precautions that should be taken for each of the examples
identified in (a)-6 Marks
a) Damaged Cables :- Damaged electrical cables and sockets may leads to fire in the
workplace .it is happens due to overheating in plug point. Inadequate standard electrical
equipments :- Usage of non approved standard electrical equipments leads to damages
and fire. Overloading of electrical connections into socket :- Number of electrical
equipment plugged into one socket
increase the overload and cause fire ,Using of
electrical equipment in wet conditions :
- If the electrical equipment is not permitted
use in damp condition may lead to electrical shock . Loose cable Joints:- one of the most
common causes of overheating . Bunching of cables :- Can also cause excessive heat to be
developed within the inner cable, leading to fire . Incorrect rated fuse:- may lead to
failure of electrical equipments and total building, Lack of Earthing :- lack
of
adequate
earthing may increase the risk of fire ,electrocution etc..
b) Electrical equipment and circuits are normally rated to carry given safe current which
will keep the temperature rise of the conductors in the circuit .to avoid the fire hazards due
to overloading the system has to be provide with Miniature circuit breakers
.Modern
mutli -Plugs are much safe as they lead to one fused plug , Avoid loose cable connections
and joints should be properly insulated . bunching of cables should be avoided and
properly laid through cable tray .Provided with correct rating fuse and earth connections
properly checked and earthing should be done properly .The electrcial equipment should
provide with earth leakage circuit breakers or ground fault circuit interpreter. Adequate
maintenance and polarity test ,Use of ingress protection male and female sockets .Flame
proof electrical equipments
8) Outline a range of checks that should be made to ensure electrical safety in an office
environment -8 Marks
Visual inspections for damage to cables, plugs and sockets, the need to ensure that all fuses
are of the correct rating, and checking that equipment is sited such that outlets are not
overloaded and cables are not in vulnerable positions. The equipment itself should be
checked to ensure suitability and conformity with recognized standards (e.g. CE Marking)
for Europe and a specific testing procedure for portable appliances should be in place, as
well as a procedure for reporting defects or damage. Check for the proper earthing and the
connection are through earth leakage circuit breakers (ELCB /RCD).Plug and sockets of the
equipment are to be checked and cables are routed properly.
9) Outline practical measures to reduce the risk of injury from electricity when using
portable electric tools-8 Marks
Practical control measures are to be implemented to reduce the risk of injury from
electricity Operate electric tools within their design limitations and connections are to be
taken through ELCB / RCD .Disconnect power when not in use and ensure that it do not
start accidentally
Ensure that cords from electric tools do not present a tripping hazard Do not use electric
tools in damp or wet locations unless they are approved for that purpose. Keep work areas
well lighted when operating electric tools and Ensure earthing is given. Use adequate
personal protective equipments while using electrical equipments . The cables used for
electric cables should double insulated .Use reduced voltage equipments with 110 volts and
while doing any maintenance do the isolation
10) Outline measures that should be taken to minimize the risk of from electrical
equipment -8 Marks
Hazards associated with the use of electrical equipments can be controlled through their
proper use and care. It is necessary to establish safe work practices in compliances with
safety rules for the use electrical equipments at the workplace. To avoid the risk of
electrocution the following should be taken into consideration; Electrical supply to the
equipment should be taken through proper fuse, power supply to the electrical tools should
be taken through ELCB / GFCI, plug casing should be free of damages, electrical equipments
should be provided with proper grounding. The use of two layer of insulating materials
around the electrical equipment (Double Insulation) avoids the need for an earth conductor
as there is no exposed conductor which may become live. Shut off the electrical supply to
the equipment when not in use and preventing the system from being mistakenly operated.
Do not use the equipment in damp or wet location unless they are approved for that
purpose.
11)When using a portable electrical grinder to cut a support beam at height, the
operator accidentally makes direct contact with the supply cable.
a) Identify four possible outcomes associated with this action-4 Marks
Damaged Cables :-Frayed cables may cause direct contact with the person
Damaged Body the Electrical Grinder :- Electricity may leak into the body through
damaged body parts of the machine.
Overloading of Grinding machine :- Inadequate grinder wheel or giving more overload to
the equipment may increase the
chance for short circuit and may lead to
electrical shock
Failure of Residual current device :- Such as failure of ELCB may cause return current
and may cause electrical shock
Inadequate Earthing :- Lack of proper earthing , discontinuity in earthing increase the
chances shock
b) Identify four protective devices /systems that could minimize the risk to the
operator in these circumstances-6 Marks
Fuses: Fuses come with a current rating and in case the amount of current exceeds the
specified limits it melts to disconnect the electricity flow and provide protection.
Earthing: Electricity will always try to reach earth and earthing is a means of providing a
low resistance path to earth
Reduced Voltage System: Reducing the mains voltage by means of a transformer to a
lower safer voltage e.g. 110volts or 55 volts
Isolation: Shutting off the electricity supply toan item of equipment and preventing the
system from being mistakenly reconnected
Residual Current Devices (RCD):-an electrical device which protects personnel by
detecting potentially hazardous leakage current and quickly disconnecting power from the
circuit.
Double Insulation: Two separate layers of insulation are provided which allows for fault
detection where one layer has failed the other still provides protection
12) A joiner has received an electric shock from a hand –held 230v drill while fitting
floor boards to an upstairs room of new property .the drill is five years old but has
not been tested during this time .fortunately the injury to the joiner was not serious.
a) Identify the factors that may have limited the severity of injury on this occasion -4
Marks
The drill machine is connected with earth leakage circuit breaker/residual current circuit
breaker and proper earthing was given to the drill machine, The body of the electrical
portable drill was double insulated and double insulated cables was provided and regular
portable appliance testing was done with the equipment and regular maintenance .The
operator was provide with adequate personal protective equipment.
a) Outline the physical effects on the body that such contact with electricity could
have caused under different circumstances …4Marks
when the body is exposed to electrical shock
 Damage to nervous system
 Irregular heartbeat (fibrillation)
 Internal burns
 Muscular contractions
 Physical trauma
 Stopping breathing (respiratory paralysis)
 Surface burns to the skin
Such health effects may be so severe that they ultimately result in death. They may also
result in secondary effects such as being thrown off a ladder.
c) Outline ways of minimizing the risk of serious injury from electricity when using a
portable electrical drill-6 Marks
To minimize the risk of serious injury from portable electrical drill ,the connection
should taken through residual current device such as earth leakage circuit breaker or
GFCI -Ground fault circuit interrupter .The cable should be double insulated and fuse
should be provided .It is better to use with reduced voltage portable electrical 110 volts
or 55 volts .Earthing continuity has to be maintained .while operating the portable
electrical drill provide suitable personal protective equipment. Regular maintenance,
user checks and Portable appliance testing to be done .
13)Outline the factors to consider when determining the frequency for the
inspection and testing of electrical equipment -6 Marks
As per Manufacturer recommendations
The type of work activity and the Environment conditions
The duration of use and how many year old
As per the internal inspection schedule and risk assessment
As per the legal requirements
14) Identify pre use checks for electrical safety that should be carried out on a portable
drill- 4 Marks .
 Users can inspect portable equipment prior to use to identify visible defects such as damage
to insulation or loose plugs and cord grips, check of any in service date and the date of the
last PAT-portable appliance testing Inspection. Earthing and residual current devices are to
be checked , Equipment is of an approved standard and The wiring and casing are free from
mechanical damage.Cables are correctly routed to avoid damage or tripping hazards .Check
the system is not overloaded and The fuse is correctly rated
15) Identify the electrical hazards that could be discovered by visual inspection-6 Marks
Damaged electrical plugs and sockets ,
Loose cabling and damaged sockets
Missing of PAT inspection tag
Loose earthing and failure in residual current devices
Overloading and damp conditions
Inadequate cable management system
Damaged Fuses and body of the equipment
16) (a) Outline the three levels of inspection that should be included in a
maintenance and inspection strategy for portable electrical appliances-8 Marks
The following three inspection procedures are in place:
 User checks
 Formal visual inspection
 Combined inspection and test by a competent person
 User checks
Users can inspect portable equipment prior to use to identify visible defects such as
damage to insulation or loose plugs and cord grips, check of any in service date and
the date of the last PAT Inspection.
 Formal visual inspection
A formal visual inspection is an inspection carried Out by an individual with
electrical knowledge to Determine whether: Damage to insulation or loose plugs and
cord grips, check of any in service date and the date of the last PAT-portable
appliance testing Inspection. Earthing and residual current devices are to be checked
, Equipment is of an approved standard and The wiring and casing are free from
mechanical damage.Cables are correctly routed to avoid damage or tripping hazards
.Check the system is not overloaded and The fuse is correctly rated
 Combined inspection and test by a competent Person
A polarity test ( carried out on extension cables and supply leads to ensure that live
and neutral conductors are wired correctly )
 Earth continuity test
 Insulation Resistance test
 Earth leakage test
(17) Identify the reasons for keeping centralized records of the results of portable
appliances testing within the oragnsaition-4 Marks
 Whether the machine is inspected by an authorized person.
 In case the test label is removed the record would help to identify inspection date
 To ensure the inspection and test are done as per schedule.
 History of the records helps to assess the machine condition.
18) Outline precautions to protect against electrical contact when:a) Excavating near underground cables -6 Marks
Precautions are to be taken while excavating near to underground cables such as detect the
location of cable by using cable detector and obtain shut down for the live line with lock
out an tag out system .Do manual excavation where up to the cable found and provide
adequate protection and continue with the mechanical excavation use insulated tools for
digging. The hazards are to be controlled by work permit system. The work activities
should be carried out by competent persons and appoint a supervisor to monitor the work
activities, Provide Adequate information and instructions and implement the safe working
method . In case of emergency follow the emergency actions .Adequate personal protective
equipment and barrication. Detailed job safety analysis to be done
b) Working in the vicinity of overhead power Lines -6 Marks
Precautions are to be taken to prevent the contact with the over head power line the best
method avoid working under overhead line, while working in the vicinity of power lines
establish a permit work system and it should be supervised by competent persons
.Personal protective equipment and insulated equipment are to be used .Another better
option to do the isolations and for providing information in terms of using barriers,
signage's goal posts to keep plant and vehicles a safe distance from power lines. For the
vehicle movement near to the overhead power line deploy banks men for controlling the
operation and use non conducting equipment such as fibre glass ladders.
Element 6
Fire Safety
Fire Triangle:
Key components of “Fire Triangle”
1) Oxygen: Oxygen is the most common oxidizing agent; it supports the combustion but does not
burn.
2) Fuel: Fuel is any substance that can undergo combustion. It exists in three states of matter:
Solids, Liquids & Gases.
Solid combustibles like paper, furniture, clothing and plastics
Flammable liquids like petrol, oils, kerosene, paints, solvents and cooking oils / fats
Flammable gases like natural gas, LPG, acetylene
3) Heat: The heat given off by the oxidation reaction sustains the fire once it is established. But
first, a heat source is required to produce ignition.
Sources of Ignition:
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.)
Fire Prevention:
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
equipment’s 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.
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.
Common causes of fires in the workplace
1)
2)
3)
4)
5)
6)
7)
8)
9)
Electrical Equipments
Mechanical heat
Open Flames
Smoking and matches
Deliberate Ignition
Overheated materials
Chemical Reactions
Unsafe storage of materials
Use of flammable liquids or gases in unsuitable areas
General Role of Fire Marshal:
The general roles of fire marshal during an emergency evacuation of a workplace in the event of a fire
are: Raising of alarm, 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 equipment’s such as an “evac - chair”. He should make sure
that fire doors are closed to prevent fire spread to adjoining compartments and to protect the escape
routes. 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.
Fire Classification
Class A – Solid materials –Fires involving solid materials such as Paper, Wood, Coal and Textiles
Class B – Flammable Liquids – Fires which involve liquids or liquefied solids - Petrol, Oil and
Solvent
Class C – Gases – Fires which involves gases such as Methane, Propane, Acetylene
Class D – Metals – Fires involving materials such as aluminum, magnesium etc.
Class F – High temperature fats and oils
Methods of Heat Transfer:
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.
Principles of Extinction
1. Cooling: Cooling is the process of depriving (removal) the fire of heat i.e. by applying substances
such as water that will absorb the heat from fire and thereby reducing the fire’s temperature
below the critical level needed to sustain the fire.
2. Starvation: Starvation is the process of depriving (removal) the fire of fuel i.e. Combustible
materials
3. Smothering : Smothering is the process of depriving (removal) the fire of the oxygen needed to
sustain the combustion process
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.
Fire Prevention Techniques:
Eliminate or reduce the storage of flammable materials
Control ignition sources
Control smoking and smoking materials
Good housekeeping
Lubrication of machinery to prevent friction
No overloading of electrical systems
Regular inspection of electrical systems
Ventilation outlets not obstructed
Controlling hot work within work permits
Proper storage of flammable liquids
Segregation of incompatible chemicals
Security to prevent arson
Regular inspection and supervision
Factors to consider for safe means of escape from building in the event of fire:
Following factors need to be considered for a safe means of escape:
Fire Doors:
1. Fire doors should open in the direction of travel (outwards).
2. Doors providing means of escape should never be locked
3. Display notice on the doors.
4. Signs along escape routes,
5. Corridors and stairways forming a means of escape should have half-hour fire resistance.
6. Corridors and other escape routes must be unobstructed
Escape Routes:
1. Where two or more escape routes are needed they should lead in different direction to safety
2. Escape route need to be short and should lead people directly to a safe place such as open air or
an area inside the workplace where there is no immediate danger.
3. Escape route should be wide enough for the required number of people to move through it
Lighting:
Escape route should be provided with adequate ventilations. If the route has only artificial lighting or if
it is used during the hours of darkness, alternate source of lighting should be considered in case of
power failure due to fire.
Element 7:
Chemical and Biological Health Hazards and Risk Control
Biological Agents:
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, Leptospirosis, Weil etc.
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.
Mould: These are special groups of fungi which are usually seen on the surfaces of bread,
cheese, leather etc. under the presence of damp condition (moisture, low air circulation area)
The three possible routes of entry of biological agents into human body can be in the following
ways.
1) Inhalation: Agents 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.
2) 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.
3) Injection: Biological agents can pass through the skin barrier through damaged skin.
Control Measures:
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
Personal Hygiene: Keeping the body clean and washing the hands before having food
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 (rats, bats etc.) that
may spread diseases should be carried out.
Immunization: Immunization can be performed so as to increase the resistance power
against specific infections caused by the micro organisms (Vaccination)
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
Adequate usage of personal protective equipments like aprons, gloves, masks etc.
Specific Training (IITS): Employees working with biological agents should be provided with
specific trainings related to the hazards, risks and control measures associated with the
work activity.
Toxic chemicals can enter the human body in different ways (Routes of Entry):
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 from where it can spread to different parts
of the body. Chemicals in the form of solids, liquids etc. can enter the human body through this
route
Absorption: Substances passes through the skin pores, conjunctiva, mucous membrane etc. and
into the tissues beneath and then into the blood stream which will then spread to different of
the body. Chemicals in the form of liquids, mists etc. can enter through this route.
Injection: Chemicals can pass through the skin barrier by physical injection or through damaged
skin.
Dose:
Due to dose there can be 2 types of effect on the human body 1) Acute health effect and 2)
Chronic health effect
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 certain 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.
Body Defenses to dust – Inhalation, Ingestion, Absorption
1) Inhalation:
Nose: On inhalation many substances and minor organisms are successfully trapped by
nasal hairs
Respiratory Tract: On detecting harmful substances a series of reflexes activate the
coughing and sneezing mechanisms to expel the substances.
Ciliary Escalator: Microorganism or dust are caught in the sticky mucus and moved up by
the ciliary escalator.
2) Ingestion:
Mouth: Saliva in the mouth provides useful defense to substances which are not excessively
acid or alkaline or in large quantities.
Gastrointestinal Tract : Acid in the stomach provides a similar defense to saliva and vomiting
and diarrhea are additional defenses to remove substances
1.
2.
3.
4.
3) Absorption:
Sebum: Secreted by the sebaceous glands of the dermis will provide protection against water,
weak acids and alkalis. Prevents the skin drying out when subject to heat and friction.
Melanin: Provides protection against ultra violet light and tans on exposure to sunlight.
Blisters, Rashes, Inflammation: These are indications of the body's defense systems reacting to
damage.
Sensory Nerve Cell: These alert the brain to temperature changes and prompt involuntary
defense action by the muscles (shivering).
4) Injection:
Scavenging action: A white blood cell called macrophages attacks invading particles in order to
destroy and remove them from the body. This is known as phagocytosis.
Secretion of defensive substances: Some specialized cells release substances to combat
harmful substance such as heparin which promotes the availability of blood sugar.
Prevention of excessive blood loss : Preventing excessive blood loss is done by blood clotting
and coagulation which also slows or prevents the entry of germs
Repair of damaged tissues : The body can repair damaged tissue which also includes the
removal of dead cells, increased availability of defender cells and replacement of tissue strength
e.g. scars tissue
Sources of Information:
The sources of information which could be used in the assessment of risk of toxic substances may
include the following:
Product Labels
European Union List of Indicative Limit values (EU)
Health Safety Executive List of Work place Exposure Limits (HSE - U.K)
American Conference of Government Industrial Hygienist list of threshold Limit values (ACGIH US)
Manufacturers Safety Data Sheets (MSDS)
Consultants
Chemical Risk Control Measures:
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).
Ventilations: Chemical work areas or storage areas should be provided with adequate
ventilations in the form of Local Exhaust Ventilations (LEV) or Diluted Ventilations.
Air Monitoring: Periodical air monitoring should be performed to make sure that the level of
airborne concentration of chemical is within the permissible limit.
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 and General environmental hygiene: The personal cleanliness of workers and their
general environment is a very important factor in occupational hygiene control.
Personal Protective Equipments: PPE should be used in combination with other control
measures if adequate controls cannot be achieved otherwise
IITS: Employees should be informed & instructed about the hazards associated with the work
activities, he should be properly trained and his work should be supervised.
Information’s included in Manufactures Safety Data Sheet
The information generally found on safety data sheets includes:
1) Information of Chemical
Product Name
Chemical Name / Chemical Formula
Identification of substance / preparation
The manufacturer /supplier
Composition/information on ingredients
Physical and chemical properties
Stability and reactivity
Toxicological information
Ecological information
2) Information about the Hazards
Hazard identification
Health effects
3) Information about the Precautionary Measures
First aid measures
Fire fighting measures
Accident release measures
Handling and storage
Transport information
Exposure controls
Personal Protective Equipment
4) Environment Information:
Environmental / disposal considerations
Disposal considerations
5) Others
Regulatory information
Other relevant information
Occupational Dermatitis & Control Measures:
(a) The below mentioned substances can cause contact dermatitis: Solvents, clay, plaster, glues,
detergents, thinners, cements, detergents, acids & alkalis etc.
(b) Control Measures: 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.
Wood Dust (Application):
(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.
Chemical Agents / Forms of Hazardous Substances:
1. Solids: A solid block of material. Substance having a definite shape and volume under normal
temperature and pressure.
2. Liquid: A basic state of matter. Substances having a definite volume but no definite shape under
normal temperature and pressure
3. Gas: A basic state of matter. Substances having neither shape nor volume under normal
temperature and pressure.
4. Dust: Tiny solid particles slightly heavier than air, dispersed in air for a short period of time and
these are normally generated by activities like grinding, polishing, milling, blasting etc.
5. Smoke: These are tiny non combustible solid particles dispersed in air for a short period of time.
6. Vapors: Vapours are normally generated when a liquid or solid reaches or nears its boiling point.
Asbestos:
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
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.
Workplace Exposure Limits (WEL):
The maximum airborne contamination of chemical to which a person shall be continuously exposed for
a certain reference period
Short Term Exposure Limit (STEL): The maximum concentration of a chemical to which workers may be
exposed continuously for up to 15 minutes without danger to health or work efficiency and safety.
Long Term Exposure Limit (LTEL): The maximum concentration of a chemical to which workers may be
exposed continuously for up to 8 hours without danger to health or work efficiency and safety.
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
Hazardous & Non Hazardous Waste:
Hazardous wastes are those which are 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.
Bunds:
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.
Element 8:
Physical and Psychological Health Hazards and Risk Control
Health Effects due to Noise
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
Two types of Noise Control Techniques:
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
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: Poor quality materials used for the manufacture of personal
hearing protection will reduce its effectiveness
Incompatible with other personal protective equipment’s: If the size of the ear muff or ear plug is large, it will
be difficult to use it with other PPE’S
Ergonomic Issues: Sometimes the weight / size of the personal hearing protection can have an impact on its
effectiveness
Lack of Awareness: If the employees are not provided with adequate training regarding the use of the personal
protection , they may not use it in a proper way which can reduce its effectiveness
Noise Control Measures:
Try not to use any sort of equipment or machinery that produces a high level of noise in the workplace environment. If it
is not possible to eliminate, substitute the equipment with other one that produces less amount of noise (advanced
techniques). Silencers can be provided on the exhaust pipes of the machines to reduce the amount of noise generated
(Engineering Control). Usage of rubber bushes on the legs of the machine or usage of insulating floor mountings will
help to reduce the structure born vibrations thereby reducing the noise (Engineering Control - Damper). Laggings can be
provided on the pipelines carrying fluids to reduce the sound transmission. Enclosures can be provided on the
equipment (Isolation), which uses sound insulating materials thereby reducing the sound generated from the source.
The position of the machine should be changed or distance should be maintained between the source and the receiver
(Isolation by Distance). The exposure time of the employee with noise should be reduced by providing job rotations and
frequent rest breaks (Administration Controls). Periodical health surveillance should be provided to employees
exposed to high levels of noise (Administration Controls). Employees should be provided with adequate personal
hearing protections like ear muffs, ear plugs etc. Employees exposed to noise should be informed and instructed about
the risks associated with their activity, they should be thoroughly trained in their work and their work should be
supervised.
Vibration
Symptoms / Health effects –
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
0R
Hand-Arm Vibration Syndrome (HAVS):
Vibration White Finger
Nerve Damage
Muscle Weakening
Pigmentation
Whole Body Vibration Effects (WBV):
Back Pain
Spinal cord damage
Vibration Control Measures:
Elimination: Try not to use any sort of equipment or machine that produces a high level of vibration or use
mechanization or automation; substituting the tools / equipment with lower vibration producing equipment; Vibrations
transmission from the equipment to the operator should be reduced by the usage of rubber grips. The operators
exposure time with the vibration should be reduced by providing job rotations, frequent rest breaks etc. Periodical
health surveillance program should be planned to check the health effects on employees exposed to vibration;
introducing a planned maintenance program (lubrications) for the tools and providing appropriate personal protective
equipment such as gloves to keep hands warm. Employees exposed to vibrations should be informed and instructed
about the risks associated with their activity, they should be thoroughly trained in their work and their work should be
supervised.
The factors that affect the risk of injury due to vibration include the following:
The frequency of the vibration
Magnitude of energy
Strength of grip
Exposure time
Frequency of exposure
Low temperature
Individual factors of the employees exposed to vibration e.g. health, age etc.
Ionizing Radiation:
Four different types 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
Health Effects – Ionizing Radiations:
Acute Effect:
Radiation Sickness – Nausea & Vomiting
Blistering
Ulceration
Pigmentation
Chronic Effects:
Cancer
Sterility
Cataracts
Genetic Effects
Ionizing Radiation – Control Measures:
By reducing the time of exposure of employees with 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 (waste) radiation materials should be disposed of 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.
Non Ionizing Radiation
The different types of non-ionizing radiations can be selected from the following list of radiations:
 Ultra violet rays – UV rays: These are high frequency electromagnetic radiations. Ultra violet rays can be raised from
welding operations or excessive exposure to sun
 Infra-red rays – IR rays: Lower frequency electromagnetic radiations. These rays are emitted during the gas cutting
operations, glass manufacturing areas, red hot steel in rolling mills
 Lasers – These are electromagnetic radiation between the UV and IR frequencies, visible to human eye. Lasers shall be
emitted from the laser equipment’s
 Microwave – These are lower frequency electromagnetic radiations emitted by microwave generators. These include
rays generated from the microwaves, radar and telecommunication equipment’s
Health Effects – Non Ionizing Radiations:
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.
Advantages & Disadvantages – Ear Plug & Ear Muffs:
(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.
Occupational Stress
Symptoms of Occupational Stress
Depression
Anxiety
Drop in work performance
Increase in absenteeism
Sleeping difficulties
Fatigue
Headaches
Heart palpitations
Gastrointestinal upsets
Increased aggression
Factors Causing Occupational Stress:
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.
Control Measures:
Work load, deadlines etc. should be reasonable and where possible should be designed in consultation with the workers:
Employees should be provided with adequate information, instruction and training to increase their awareness and
knowledge about their work: Employees should be provided with adequate and safe working environment to work and
shall also be provided with adequate resources to perform their task in a competent manner: Strict policies, rules and
regulations should be implemented to avoid bullying, harassment and discrimination within the workplace: Workers
should be given as much control of their work as possible: Good management support to employees will help to ease
down the certain level of occupational stress: Employees should be clear about his roles and responsibilities to perform
within an organization.