occupational health and safety system

1. INDUSTRIAL HYGIENE
BY – IRAM DANISH
SEMT-481

2. Definition of
Occupational / Industrial Hygiene
2
• Definition 1 (International Occupational
Hygiene Association By-laws – IOHA)
“ Occupational Hygiene is the discipline of anticipating,
recognizing, evaluating and controlling health hazards
in the working environment with the objective of
protecting worker health and well-being and
safeguarding the community at large.”

3. Definition of Industrial Hygiene
3
• Definition 2 (American Industrial Hygiene
Association - AIHA)
• “That science and art devoted to the anticipation,
recognition, evaluation, and control of those
environmental factors and stresses arising in or from
the workplace, which may cause sickness, impaired
health and well-being, or significant discomfort
among workers or among citizens of the community”

4. Definitions – Industrial
Hygiene
4
IOHA AIHA
Occupational Hygiene is the
discipline of anticipating,
recognizing, evaluating and
controlling health hazards in the
working environment with the
objective of protecting worker
health and well-being and
safeguarding the community at
large.”
Industrial Hygiene is “That science
and art devoted to the anticipation,
recognition, evaluation, and control of
those environmental factors and
stresses arising in or from the
workplace, which may cause sickness,
impaired health and well-being, or
significant discomfort among workers
or among citizens of the community”

5. What is the difference between
Industrial hygiene and
Occupational hygiene?
• The term Industrial Hygiene originated in the USA while in other
parts of the world it is known as Occupational Hygiene.
• In some ways the term Occupational is a better description as health
risks occur in all places that people work such as offices, shops,
hospitals and farms, not just in places you would think of as
industrial.
5

6. Qualification of an Industrial
Hygienist
6
• A person having a college or university degree (s) in
engineering, chemistry, physics, medicine or related
physical and biological sciences, who has also
received specialised training in recognition, evaluation,
and control of workplace stressors and therefore
achieved competence in industrial hygiene.

7. Basic Principles of
Industrial Hygiene
7
1. Anticipation of potential health risks
2. Recognition of existing health hazards at the
workplace
3. Evaluation of health risks
4. Control of unacceptable risks
Remember the acronym: A.R.E.C.

8. Anticipation of
potential risks
8
• Best done –
❒ in the design stage of a process or equipment or
❒ at the formulation stage of a new substance or
chemical
Advantage: Eliminate the need for review or
redesigning, thus save high costs.

9. Anticipation of
potential risks
9
• Basic information to consider:
❒ Characteristics of the process or equipment
❒ Physical and chemical properties of the formulation
❒ Adverse health effects from past experience and
reported cases of occupational diseases and
poisoning
• The process of anticipation is not easy and requires vast
experience. Need to engage the assistance of experts
such as the industrial hygiene practitioner, toxicologist
and occupational health doctor.

10. Recognition of Health
Hazards
DipOSH_2011(Tay) 10
• This may be achieved through –
a. Workplace inspection
i. Look at workplace environment, work processes,
types of materials & equipment used;
ii. Observe workers at work

11. Recognition of Health
Hazards
11
b. Health surveillance and area
monitoring
c. Workers health records
d. Review of past Incident investigation reports.
e. Discussion with the management and workers
Area Toxic Gas
Monitoring

12. Harmful Factors that exist
at the Workplace
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• Many workers may be exposed to a number of health
hazards at work.
• Hazard recognition :
– Identifying factors or work processes that may be harmful
to health.
– Knowledge of the physicochemical properties of a material/
substance, its harmful effects to health and identification
techniques are essential.

13. Health Hazards encountered at
Work
DipOSH_2011(Ta
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1. Chemical Substances
2. Physical agents.
3. Biological agents
4. Ergonomics
5. Psychological factors.

14. Chemical Hazards
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• Hazards – risks are associated with the use ofchemicals.
• Hazardous chemicals may cause –
✓ Fire & Explosion
✓ Adverse health effects
✓ Damage to the environment
Forms of Chemicals
• Dust,
• Particles and smoke
• Liquid and mists
• Gas and vapour
Common Types
1. Solvents
2. Metals
3. Acids and Bases
4. Pesticides

15. Physical Hazards
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Excessive exposure to the following physical
hazards may cause harm to our health –
✓ Noise
✓ Vibration
✓ Ionising radiation
▪ Cosmic rays – gamma, alpha, Beta and X-rays;
▪ soil/rock radioactive elements– uranium, thorium, radium,
potassium-40;
▪ Man-made nuclear radiation
✓ Non-ionising radiation
▪ UV, Infrared, microwave, laser.
✓ Lighting
✓ Extremely high/low temperature
✓ Extremely high/low air pressure

16. Biological Hazards
•
•
•
Micro organisms
– Bacteria, viruses and Parasites.
– The virus of contagious diseases may spread
through its vectors.
Toxins (spider, snake, scorpion, jellyfish,
wasp) Plants (fungi, yeast, cotton dusts)
Bacteria Anthrax, legionnaire’s disease, botulism, E.Coli,
salmonella
Viruses H5N1(Avian Flu), SARS, HIV, mumps, Dengue fever.
Hepatitis A/B/C , Variecella (chickenpox)
Fungi Poisonous mushrooms
- Amanita virosa (DestroyingAngel),
– Amanita phalloides (Death Cap)
Parasites Malaria, mites, leeches, intestinal worms

17. Ergonomic Hazards
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Musculoskeletal disorders affecting workers may
arise from unsuitable work conditions or physical incapacity to
carry out their assigned tasks.
1. Awkward body postures

18. Ergonomic Hazards
Examples of unsuitable work conditions or physicalincapacity:
4 Poor lightning and cramp work place
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2. Manual lifting of heavy loads
3. Repetitive hand Movements

19. Psychological hazards
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Tensions at the workplace may disturb the concentration
and mental health of the worker
Examples of Tensions at the workplace
✓ Monotonous work
✓ Excessive workload and overtime
✓ Poor work relationships with colleagues and
supervisors
✓ Shift work
✓ Remuneration and annual leave issues
✓ Sexual Harassment

20. Objectives of Risk Evaluation (Assessment)
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• To determine the level of worker exposure (high, medium or
low) to health hazards and the effectiveness of the existing
control measures, and their relationship to the risk of disease.
• To enable decisions to be made on additional control
measures to bring the health risks down to within PEL
(Permissible Exposure Limit).
– e.g. engineering control to reduce airborne contaminants, worker
training, health surveillance.

21. Risk Evaluation – what to look at?
21
Risk = Hazard x Exposure
Hazard Component
= Magnitude of hazard and the potential adverse health effects from
possible routes of entry or contact.
Exposure Component
= Chances of overexposure occurring by taking into account:
i. Characteristics of
exposure
ii. Level of exposure
Risk Conclusion – takes into account the work practices and
personal factors including individual susceptibility.

22. Risk Evaluation
22
(i) Characteristics of exposure
✓ Who are exposed (based on Job types and tasks
performed)?
✓ How many are exposed?
✓ What are they exposed to?
✓
How are they exposed?
€ Inhalation
€ SkinAbsorption
€ Ingestion

23. Risk Evaluation
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(ii) Level of Exposure
• Frequency of exposure
– daily, weekly, monthly?
• Duration of exposure
– by seconds, minutes, hours?
• Intensity of exposure
– high, medium, low?

24. Risk Evaluation
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(ii) Level of Exposure
– Exposure intensity -
Quantitative
• Using equipment to measure
the intensity or magnitude of
exposure
Field Sling Psychrometer
– Exposure intensity - Qualitative
• Using observation and
professional opinion

25. Risk Conclusion
25
• Risk conclusion is made after taking into
account
i. Level of risk exposure (high, medium or low)
based on qualitative or quantitative assessment
and rated against the Industry accepted
Permissible Exposure Limits.
ii. The work practices, and personal factors
(including individual susceptibility)
ii. The adequacy of existing control measures

26. Control of Health Risks
26
Principle of Risk Control
• Prioritise the control measures at the source, not the
worker
• Prioritise the elimination of hazards, not the
reduction of exposure
• Controls should target below the permissible
exposure limits
• Controls should be as low as reasonably practicable,
especially in cases where there is no data on the
permissible exposure limit
• Use of personal protective equipment (PPE) as a last
resort

27. Principle of Risk Control
27
1.Prioritise the control measures at the
source, not the worker
❒ Controlled source means –
€Controlled exposure
€ A hazard free environment
❒ It is easier to control processes, machinery and
equipment than to control workers

28. Principle of Risk Control
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2. Prioritise the elimination of hazards, not
the reduction of exposure
❒ No hazard means no exposure
❒ Elimination of hazards is more effective
❒ Reduction of exposure is only recommended where it
is not possible to eliminate or isolate the hazard

29. Principle of Risk Control
DipOSH_2011(Tay) 29
3. Controls should target below the
permissible exposure limits
❒ Risk is reduced if worker exposure is below the
permissible limits
❒ Exposure beyond the permissible limits is harmful to
worker health
❒ Violation of Regulations, if PEL is exceeded

30. Principle of Risk Control
30
4. Controls should be as low as reasonably
practicable , especially in cases where there is no
data on the permissible exposure limit
❒ The risk of cancer or allergy exists even at low exposure
levels
❒ Hazard free environment is still the best working
environment
❒ Many chemicals do not have permissible exposure limits

31. Hierarchy of Risk Controls
31
• It is a list of protection strategies that are
rated in order of priority from the best to the
worst.
1. Elimination
2. Substitution
3. Isolation
4. Engineering controls
5. Administrative controls - Safe work practices and
procedures
6. Personal Protective Equipment (PPE)

32. Other Methods to increase the levels of
Control on health risk at the Workplace
32
• Provide Information, instruction and training to workers.
• Exposure monitoring
• Health surveillance
• First aid and emergency facilities
• Warning signals

33. Tay
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