7 Physical

7/30/2019 7 Physical

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MKH1313 – Industrial Hygiene

Dr. AA, 2010

Physical Hazards

Examples of Physical Hazards

•Excessive noise Excessive vibration Inadequate

lighting

Slip hazard Tripping hazards Exposure to radiation




Dr. AA, 2010

Physical Hazards

• Excessive noise• Excessive vibration• Inadequate lighting• Protruding objects• Tripping hazards• Exposure to radiation• Extremely hot or cold

surfaces/substances• Inadequate guarding on equipment or

machinery• Slippery surfaces• Inappropriate or damaged tools

• Exposed electrical sources•

Good Housekeeping




Dr. AA, 2010

Housekeeping

Basics of Good Housekeeping• Always keep exits and doors clear of obstructions

• Never use isles for storage – even short periods.

• Keep isles and passageways clearing delineated – eg yellow lines

• No mats or grates in stairwells

• Clearly identify all fire fighting, first aid,

emergency equipment • Clean vents etc regularly

• Only use items for the purpose they wereintended.




Dr. AA, 2010

Benefits of Good Housekeeping

•Reduce accidents, and injuries.

• Reduce the risk of fire.

• More efficient work outcomes.

• Reduce fatigue.

• Increase morale.

13/02/2011

Fall & Slips




Dr. AA, 2010

Preventing falls from ladders

To reduce the risk of falls from ladders:• Use ladders with slip-resistant feet

• Inspect ladder before climbing

• Do not use chairs, boxes, or tables as asubstitute for a ladder

• Set ladder on a flat, firm surface

• Face the ladder when standing on it and whenclimbing up or down

• Keep the center of your body between the side

rails of the ladder

• Don’t work from the top two steps of a ladder

Preventing falls from elevations

• Don’t work on an elevated floor or work locationwithout guardrails in place.

• Don’t stand on guardrails to gain extra height.

• Don’t lean over railings.




Dr. AA, 2010

Preventing slips, trips, and falls:

• Wet, slippery floors are amajor cause of slips,trips, and falls. To helpprevent accidents: – Wear safety shoes with

non-skid soles – Keep floors free from water

or grease – Clean floors regularly – Use slip-resistant waxes on

floors

– Clean up spills immediately – Put up warning signs

around spills or wet floors


• Use rubber mats in areas

where the floors are

constantly wet

• Report to your supervisor

any repair needed to non-

slip tiling or other non-slip floor products

• Report to your supervisor

any uneven floor surfaces.




Dr. AA, 2010


• Keep floors and stairs free of

debris and obstructions

• Make sure mats and carpet are

free of holes and bumps

• Report poor lighting and

replace burned out bulbs as

soon as possible

• Report or fix any other trippinghazards immediately

What are the best shoes?

To prevent slips and falls use

shoes with:

• Slip-resistant soles and a goodtread

• Tightly tied laces

• No leather or smooth soles

• No open-toes

• No platform or high heels

• No porous fabric such as canvas




Dr. AA, 2010

Preventing injuries from falling objects

If there is a risk of injury from

falling objects on the head or

feet, wear a hard hat and/or

safety shoes.

Foot that was in the crushed boot

Fall Protection: Work Positioning

Systems• These systems are designed to hold and sustain

the user at a work location and limit the free-fall

to two feet or less, as in rebar work or tree

trimming. These are examples of typical

components of a work positioning system.

• Body Support: Full Body Harness

• Connecting Component: Chain or web rebarassembly, rope or web lanyard

• Anchorage Connector: Carabiner or snap hook

• Anchorage: Rebar or Support Structure




Dr. AA, 2010

Fall Protection: Restraint Systems

• These are systems designed to prevent the

user from reaching an area where free-fall

could occur so no free-fall is possible, as in

leading edge roof work. Here are some

elements and examples of restraint systems.

• Body Support: Full Body Harness or Body Belt

• Connecting Component: Rope or web lanyard

• Anchorage Connector: Carabiner, Tie-Off

Adapter, Roof Anchor• Anchorage: Beam or Support Structure

Fall Protection: Rescue Systems

• These systems which are designed to raise or

lower a user to safety in the event of an

emergency, so no free-fall is possible. (i.e.

confined space work). The following are the

four elements of a rescue system and examples

of each:

• Body Support: Full Body Harness• Connecting Component: Lifeline (winch, self

retracting lifeline) and Y-Lanyard

• Anchorage Connector: Tripod, Davit Arm

• Anchorage: Support Structure or Surface




Dr. AA, 2010

Fall Protection: Fall Arrest

• These systems are designed to stop a free-fall of up

to 6 feet, and limit the maximum forces of a user to1800 pounds or less, as in steel erection or elevated

maintenance work. The following are the four

elements of a fall arrest system and some examples.

• Body Support: Full Body Harness

• Connecting Component: Shock Absorbing Lanyard,

Self-Retracting-Lifeline, RopeGrab

• Anchorage Connector: Carabiner, Tie-Off Adapter,

Trolly, Roof Anchor

• Anchorage: Beam or Support Structure

Fall Protection: Suspension System• These systems support and suspend the user while

being transported up or down vertically and will

not allow a free fall. Here are some elements and

examples of suspension systems.

• Body Support: Full Body Harness and a Botswain's

Chair

• Connecting Component: Lifeline (rope, rescue

positioning device) rope or web lanyard

• Anchorage Connector: Carabiner, Tripod, Davit Arm

Tie-off Adapter

• Anchorage: Beam or Support Structure or Surface




Dr. AA, 2010

Fall Protection: Common Pieces of

Equipment

Electrical Safety




Dr. AA, 2010

Electrical Hazards

Electrical hazards can be

caused by any of these:

• Faulty electrical tools

and equipment

• Faulty appliances and

wiring

• Electrical outlets

• Switch panels

• Electric transformers

Some Basics• Electricity will:

• Rule One: only travel in a circuit.

• Rule Two: always travel in the path of least resistance – damaged insulation is hazardous.

• Rule Three: always try to travel to the ground.

• Two Conditions for electrocution

1. The person offer the electricity a path of lessresistance.2. Form a part of a completed circuit.




Dr. AA, 2010

Path of Less Resistance.

• Under many conditions the body (skin) hasa low level of resistance to electricity.

• Wet skin has lower resistance than dry.• Thin skin (arm) has a lower resistance than

thick skin (palms).• Hence, resistance varies greatly depending

on the circumstances;• A minor accident in one set of

circumstances can be lethal in another.• PPE (gloves, rubber soled shoes) can

prevent the flow of electricity through thebody.

What are the Effects of Current onthe Body• Small amounts of current can have a

dramatic effect on the body:• 1-2 mA - minor shocks (can lead to more severe

accidents eg fall off roof).

• 10 mA - loose control of muscles and unable to let go of source of shock.

• 25-27 mA – Collapse and death.• 75-300 mA for only 0.25 second - causesventricular fibrillation and are almost allimmediately fatal.




Dr. AA, 2010

Preventing injuries from electrical equipment

• Inspect equipment, cords and fittings for damage prior to use

• Turn equipment OFF beforeconnecting to a power supplyand before making anyadjustments

• Make sure cords do not create atripping hazard

• When unplugging equipment, pull

on the plug not on the cord

• Keep cords away from heat,water and oil. These can damagethe insulation and cause a shock

Cord with waterproof seal

Preventing injuries from electrical equipment

• Do not use electric tools in wet conditions or damp locations

• Do not clean electricequipment with flammable ortoxic solvents

• Do not carry electrical tools by

the power cord• Do not tie power cords in knots

• Do not plug several powercords into one outlet

• When in doubt, always ask yoursupervisor




Dr. AA, 2010

Signs:Always obey warning signs

Static ElectricityReducing Accidents

• Pour flammable fluids slowly

• Bond or earth before working with the

flammable solutions

• Use metal (conductive) materials to dissipate

the static electricity




Dr. AA, 2010

13/02/2011

Noise

What is Noise ?• A sound that is unwanted because of:

– Intensity

– Frequency

– Duration

• Sound is produced by vibrating objects and

reaches a person’s ears as waves in the air orother media.

• A vibration in the air transmitted by theeardrum and bones of the middle ear to theinner ear.




Dr. AA, 2010

Least

Severe

150

140

130

120

Car Stereo, Band Practice

110

Dance Clubs, Headphones

100

Factory

90

Subway

80

Busy Street

70Restaurant

60Decibels

Normal

Speech

Jack-Hammer, Rock Concert

Gun Shot

Jet Take - Off Most

Severe

150

140

130

120

110

100

90

80

70

60Action Level

(85 dBA)

NoiseLevels:

Noise Risk Factors

Intensity: The loudness of sound, or the pressure it exerts through

the ear.

Hearing Safety

• If you have to shout at 3 feet in order to beunderstood you should be wearing hearingprotection.

• Off-the-job activities (woodworking,shooting, etc.) can hurt your hearing. Hearing

protection is recommended.• Never remove hearing protection in high

noise areas.

• Do NOT share hearing protection with others.




Dr. AA, 2010

Types of

Hearing Effects

Physiological Effects:

Psychological

Effects:Interference

With Communication

Explain how hearing loss

occurs

It is noise-induced loss or aural pain,

nausea and reduced muscular control.

Effects such as depression

and nervousness are a result

of the ear’s inability to adjust to sound (i.e. disrupt

concentration of sleep).

Not being able to communicate

well with others can cause

arguments, depression,loneliness, and a sense of

helplessness.

Inner EarOuter Ear

Middle Ear

Explain how hearing loss occurs

Outer

Ear

Inner

Ear

Middle

Ear

Human ear

has 3 Parts

Has three tiny bones and ear drum

which can rupture from sudden

high sound pressure level.

Has cochlea with tiny hair cells connected to

nerves. It signals the brain, which lets you know

what sound you heard. Damage is irreversible.

The outer ear or pinna, funnels sound waves into the

ear canal, which will lead to the eardrum. It will catch

dirt and particles in the canal that contains cerumen or

wax.




Dr. AA, 2010

Categories of Hearing Loss

• Conductive Hearing Loss: – Occurs when the sound vibration from the outer

and middle ear is unable to stimulate the inner ear,

due to some form of interference but the inner ear

functions normally.

– The outer ear is generally susceptible to physical

damage or infection.

– Possible causes of a conductive loss include:

• A build-up of fluid in the middle ear.

• Wax in the ear canal.

• Puncturing of the eardrum.

Categories of Hearing Loss Cont.

• Sensory Hearing loss:

– Damage to or a malfunction of the inner

ear, auditory nerve, or the brain.

– The causes of Sensory Hearing loss:

• Genetic Disorders.

• The natural aging process.

• Exposure to loud noises.

• Infection or other disease.




Dr. AA, 2010

Categories of Hearing Loss

Cont.

• Aging – Presbycusis:• The gradual loss of hearing due to increasing age.

– Two theories of Presbycusis:• Caused by changes of blood supply to the inner ear that

decreases with age.

• Cumulative effect of noise exposure.

• Exposure to Noise – Prolonged exposure to loud noise can also destroy

the sensitive hair cells of the cochlea.

– Brief exposure to loud noises (85 dBA or louder)can also cause a temporary damage.

Categories of Hearing Loss Cont.

• Symptoms of Over Exposure

– Do Not ignore these symptoms:

• Dullness in hearing.

• Ringing in the ear (Tinnitus).

• Difficulty hearing a conversation against a noisy

background.

– Other Dangers of Noise:• Increased Fatigue, errors.

• Increased Stress and/or irritability.

• Elevated Blood Pressure.

• Decreased Productivity.




Dr. AA, 2010

41

Noise Hazard Evaluations may be

performed by:

• Industrial Hygienists –

(primary

responsibility)

• Audiologists

• Trained technicians

42

Equipment Used

• Sound Level Meter(SLM) – used toscreen for noisehazards

– if the screeningdetects noise levelsabove 84 dB, adosimeter is thenused to determineindividual noise dose




Dr. AA, 2010

43

Equipment Used (cont.)

• Dosimeter – measures the average decibel

exposure level over an 8 hour day

44

Types of Sound Level Meters

A. Type 1 – Precision Laboratory Meter

• Very expensive

• Allowable variance is +/- 1 dB accuracy

B. Type 2 – General Purpose

• Allowable variance is +/- 2 dB accuracy

C. Type 1 or Type 2 may be used forhearing conservation purposes

D. Impulse noise measurements requirea special meter with peak holdingcapability




Dr. AA, 2010

45

Care of the Sound Level Meter

• Must be electroacoustically

calibrated annually

• Calibration must be

checked both before and

after measurements are

taken

• Kept in a dry, safe place

Hearing Prevention Methods:Engineering Control

• Enclosure – Provide an easy, secure and effective way to isolate noisy

machines.

• Sound barriers – Materials used to stop sound from a noisy machine or

equipment.

• Sound proof cabs – Better design of machinery & equipment, insulate the

machinery to reduce the noise & isolate workers insoundproof booths.

• Equipment and exhaust – Proper maintenance of equipment & exhaust prevents

the extra noise of machine & dirty exhaust.




Dr. AA, 2010

Hearing Prevention Methods:

Administrative Control

• Decreasing the exposure time

– Limiting the amount of time a worker spends in a

high noise area to less than 8 hours.

• Limiting the number of personnel exposed

– The number of employees working in the noisy area

should be limited to the absolute minimum.

• Arranging a work roster system – A roster system could be arranged when employees

are not working in the same areas everyday.


PPE (Ear Plugs)

• These devices fit into the ear canal between the outer and

middle ear and block the sound from reaching the sensitive

inner ear. Made of foam material that is rolled and inserted,

expands to fit snugly.

• Advantages: Small, inexpensive, portable, comfortable in warm

weather, disposable, can hear others speaking.

• Disadvantages: Requires a good fit, cannot be inserted with dirtyhands, cannot be worn with ear infections, might become loose

over time.

• How to fit and wear: Wash hands, roll and compress into a

cylinder. Reach one hand around the back of the head and pull

ear up and out. Insert into the ear canal. Hold in place until it

begins to expand and excludes noise.




Dr. AA, 2010


PPE (Ear-Band)• Over the head, in front the neck

and behind the neck.• Advantages

– Soft pieces pressed against earcanal by spring-loaded band.

– More convenient than earmuffs. – Can provide adequate protection. – Flexible tips. – Do not extend into the ear canal. – Only cover canal opening.

• Disadvantages – May become uncomfortable over time. – Soft pieces are bulky for some employees. – Cannot be inserted with dirty hands.

Hearing Prevention Methods

PPE (Earmuffs)• This style protector consists of cups which fit over the

entire outer ear to help seal out noise. May beconnected to the hard hat or held together by a headband.

• Advantages – Can be worn with ear plugs for extreme noise exposure.

Reduction of approximately 28-50 dBA. Easy to put onand remove. Can be worn despite ear infections.

• Disadvantages – Bulky and can be uncomfortable in warm weather.

• How to fit and wear

– Cushioned caps connected by a spring loaded headband.

– Adjust the headband to ensure that the sealsare in complete contact with the head. Ensure the ear cupfits over the entire outer ear.




Dr. AA, 2010


Noise Hazard Signs

• Used when engineering controls do not work,or are not feasible.

• Use Yellow and Black signs to mark hazards.

– Large signs for entire areas.

– Small stickers for individual equipment.

• Post areas as Hearing Protection Required if

sound levels at or above 90dBA.

Hearing Conservation ProgramRequirement

• Protect workers from risks to their hearing caused bynoise.

• Prevent hearing loss and deafness as a result of exposure to noise at work.

• Identify noise problems and if noise levels are above85dB(A), measurements must be taken and assessedby a competent person.

• General duty to reduce the level of noise exposure byengineering or administrative means.

• If noise level is above 85dB(A):

– Inform employees of the noise levels present and measures

taken to reduce exposure.

– Make ear protection available and provide training in its use

– Hearing checks must be made available to employees exposed

to noise levels in excess of 85dB(A) over an 8 hour TWA.




Dr. AA, 2010

Excessive Heats/ MachineryProtection

Preventing injuries from machinery

• Become familiar with the hazardsassociated with particularmachines.

• Do not work with or around

machinery in which safeguardshave been removed.

• Report to you supervisor about adamaged or missing safeguard.

Machinery with moving or rotating parts must be

equipped with guards.




Dr. AA, 2010

Preventing burns from hot equipment

• Do not handle or touch hot (orthose that may be hot) articlesor surfaces with bare hands

• If needed, wear heat-protectivegloves

• Organize your work area toprevent contact with hot objectsand flames

• Open hot water faucets slowlyto avoid splashes

• Report any faulty equipment toyour supervisor

Preventing injuries from sharp objects, scrap

metal, broken glass

Never pick up sharp objects, scrapmetal, broken glass with barehands.

Use dust pan and brush, heavygloves.

Never put sharp objects such asneedles, razor blades, or brokenglass into waster bins without wrapping and labeling the itemscarefully to protect those emptyingthe bins.




Preventing illness from working in hot

environments

• Where possible, use ventilation to draw heat andsteam away from work areas

• Isolate or insulate hot equipment, where possible

• Drink plenty of water

• Use cool rest areas near the work area for breaks

• Use cooling fans to increase air speed and sweat evaporation.

• Where possible, do heaviest work during coolest times of the shift

• Recognize the signs and symptoms of heat stress

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7 Physical