What is a/an
Hazard
Risk
Exposure
What are the types of occupational
hazards?
Learning objectives
Hazard
Potential of an agent to cause harm
Exposure
Contactwith a Hazard is called Exposure
Exposure is a combination of
Magnitude
Frequency
Duration
Risk
Likelihood that an agent will cause harm in the
actual circumstances of exposure
RISK occurs only when there is
ExposureHazard
Health Risk =Hazard x Exposure
Exposure
Hazard
Health Risk
No Hazard = No Risk
Hazard, but no Exposure = No Risk
Health Risk = Hazard x Exposure
HAZARDS AT WORKPLACE
Physical
Chemical
Biological
Psychosocial
Ergonomics
Mechanical
Classes of Hazards
Chemical
Physical
Biological
Ergonomic
Psychological
Health hazard
The potential to cause
harm to health
Occupational
Hazards
•Noise
•Vibration
•Radiation
•Lighting
•Heat
•Cold
•Fibres
•Dusts
CHEMICAL
•Fumes
•Gases
•Aerosols
•Mists
•Liquids
•Vapours
•Bacteria
•Fungi
•Insects
•Viruses
•Manual handling
•Repetitive movement
•Restrictive working area
PSYCHOLOGICAL
•Job stress
•Job monotony
•Unsociable hours
•Job organization
ERGONOMICALBIOLOGICAL
PHYSICAL
Physical hazards
Physical hazards
Fall from heights e.g. scaffolding, high building
Slips and trips
Objects falling from cranes
Dangerous heavy machinery
Electrocution
Confined spaces
Physical agents
NOISE
Noise Induced Hearing Loss (NIHL)
Mental irritability & fatigue
Noise can increase blood pressure
Interference with communication can lead to
accidents eg. Carpentry, quarry, construction
workers
CHEMICAL HAZARDS
Solvents
Dusts (sand, asbestos, cotton)
Paints
Pharmaceuticals
Pesticides
Metal fumes
Acids & Alkali
which may be
present in the
working
environment as
gases, vapours,
mists/aerosols,
fumes, dusts, liquids
or solids.
BIOLOGICAL HAZARDS
Bacteria
Fungi –mold
Virus –Bird Flu, Influenza, SARS
Blood-borne pathogen -HIV, AIDS, Hepatitis
Tuberculosis
e.g. farmers, health care workers, animal
handlers
Psychosocial hazards
Psychosocial hazards
Work-related stress –excessive working time,
overwork, burnout
Bullying –emotional, verbal
Sexual harassment
Violence at work
Body odour
Health effects:
Occupational Stress, Anxiety, Depression
Cardiovascular Disorders, GI Disorders
Drug abuse, smoking
ERGONOMIC FACTORS
•Working postures / chairs
•Space per work shift
•Working surface height
•Reach / machine feeding
•Space between machines
•Strenousphysical load
ERGONOMIC FACTORS
Lifting heavy loads/frequent bending/repetitive &
monotonous work
Design of tools
Displays and instructions
Mental overload / visibilty
Health Effects
Musculo-skeletal disorders
Backache/back strain/neck strain
Repetitive strain injuries (RSI)
Carpel tunnel syndrome
e.g. factory workers, Health care workers,
electronic, garment workers, VDU operators
What isErgonomics?
ERGO=“work”
NOMICS=“rules” or “laws”
Ergonomics literally means “the laws of
work”
SO EXACTLY WHAT IS
ERGONOMICS?
It is study of people efficiency at their
working environment.
ItisoneofthedefinitionofErgonomics.
Itisunderstandablethatthereare
different definitionsbecause
ergonomicsisallaboutdifferences
DIFFERENCES
This are differences in size,
shape, strength and ability of
individual workers.
This differences call for
different designs in
equipment , furniture,
Workstations and routines.
ERGONOMICS
Ergonomics is used in a
workplace to help
prevent repetitive and
cumulative injuries.
3 Main ErgonomicPrinciples:
1.Work activities should permit worker to
adopt several different healthy and safe
postures.
2.Muscle forces should be done by the
largest appropriate muscle groups
available
3.Work activities s/b performed with
joints at about mid-point of their ROM
(esp. head,trunk, UE)
FACTS
•The average person working at a keyboard can
perform 50,000 to 200,000 keystrokes a day
•Overexertion & fallsare the most common
cause of workplace injury
•An average of 125,000 back injuries due to
improper lifting each year.
•Musclesoveruseresultsintinytearsinthe
musclesandscarring;thesecontributeto
inflammationandmusclestiffness
Ergonomic Factors
Two Categories of Ergonomic
Factors
1. Environmental
Hearing
Vision
General comfort andhealth
2.Physical
Environmental
Factors
Some examples of ergonomic environmental
problems are:
Sick Building Syndrome
Excessive noise
Improper lighting
Temperature extremes
Physical
Stressors
Physical stressors place pressure or stress
on parts of the body:
Joints, muscles, nerves, tendons, bones
Sometimestheseinjuriesarereferredto
as“CumulativeTraumaDisorders”(CTDs)
or“RepetitiveStrainInjuries”(RSIs)
Musculoskeletal Disorders:
Signs and Symptoms
•Decreased grip
and/or pinch
strength
•Swelling
•Fatigue
•Loss of function
•Numbness
•Burning
sensation
•Tingling
•Pain
•Cramping
•Stiffness
An ounce of Prevention is
worth a pound of
cure !
What to do??
a)Warm up & stretch before activities
that are repetitive, static or
prolonged
b)Take frequent breaks from ANY
sustained posture every 20-30
minutes
c)Respect pain positions or stop
painful activity
d)Recognize early signs of
inflammatory process
Posture
Think of posturein terms of jointposition
Static and awkward postures
leadto:
Decreasedmovement
Decreasedcirculation
Increased stress andfatigue
Maintain NeutralPosture
a)Maintain erect position of back
& neck without shoulders
relaxed
b)Position equipment & work
directly in front of and close to
your major tasks
c)Avoid static positions for
prolonged time; muscles
fatigue---MOVE to
circulation!
ModifyTasks
a)Alternate activities frequently;
rotate heavy &/or repetitive tasks
without lighter less repetitive
ones.
b)If stress become worse REASSESS
task setup & look for alternative
methods
c)Avoid repetitive or prolonged grip
activities