This document provides an overview of industrial hygiene. It defines occupational/industrial hygiene according to the International Occupational Hygiene Association and American Industrial Hygiene Association. The roles of industrial hygienists include anticipating, recognizing, evaluating, and controlling health hazards in the workplace. The basic principles of industrial hygiene are anticipation of potential risks, recognition of existing hazards, evaluation of health risks, and control of unacceptable risks. The document discusses various workplace health hazards including chemicals, physical agents, biological agents, and ergonomic/psychological factors. It also covers risk evaluation and assessment methods like workplace inspections, health monitoring, and permissible exposure limits.

1. Unit 2_Overview of Industrial
Hygiene
Diploma in OSH – Kolej Fajar, Miri
DipOSH_2011(Tay)1
Lecturer: Tay Kay Chuang (Msc. in OSH, USA)

2. Learning Objectives
State the definition of Occupational Hygiene
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State the roles of responsibilities of Industrial
Hygiene practitioners
Explain the principles of Occupational Hygiene

3. Definition of
Occupational / Industrial Hygiene
Definition 1 (International Occupational
Hygiene Association By-laws – IOHA)
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“ 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.”
http://www.ioha.net/

4. Definition of Industrial Hygiene
Definition 2 (American Industrial Hygiene
Association - AIHA)
“That science and art devoted to the anticipation,
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“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”
http://www.aiha.org/Content

5. Definitions – Industrial Hygiene
IOHA AIHA
Occupational Hygiene is the
discipline of anticipating,
Industrial Hygiene is “That
science and art devoted to the
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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.”
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”

6. PREVENTION OF EXPOSURE
INDUSTRIAL HYGIENIST
TREATMENT
OCCUPATIONAL
HEALTH DOCTOR
DISEASE
WORKERS
HAZARDS
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7. Qualification of an Industrial Hygienist
A person having a college or university degree (s)
in engineering, chemistry, physics, medicine or
related physical and biological sciences, who has
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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.

8. What is the difference between Industrial
hygiene and Occupational hygiene?
None really.
The term Industrial Hygiene originated in the USA
while in other parts of the world it is known as
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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.

9. 1. Anticipation of potential health risks
2. Recognition of existing health hazards at
Basic Principles of Industrial Hygiene
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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.

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

11. 1. Anticipation of potential risks
Basic information to consider:
Characteristics of the process or equipment
Physical and chemical properties of the formulation
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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.

12. Characteristics of Process or Equipment
Process Structure
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13. Concept of a Job Shop – a machine shop
Job Shop
• Flexible operation that may involve several
work activities to complete the job.
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work activities to complete the job.
• Uses general purpose equipment.
• Relies on the knowledge of workers to
produce a variety of products.

14. Work Activity 1 – Use of a Drill Press
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15. Work Activity 2 – Use of a Lathe
A lathe is machine tool
used for cutting, sanding,
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used for cutting, sanding,
knurling, drilling, or
deformation of a work-
piece to create an object
of the desired shape.

16. Gang Milling
Work Activity 3
Use of a Milling Machine
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17. Angular Milling
Work Activity 3
Use of a Milling Machine
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Straddle Milling

18. 2. Recognition of Health Hazards
This may be achieved through –
a. Workplace inspection
i. Look at workplace environment, work processes,
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i. Look at workplace environment, work processes,
types of materials & equipment used;
ii. Observe workers at work

19. 2. Recognition of Health Hazards
b. Health surveillance and area
monitoring
c. Workers health records
Annual Hearing Test
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c. Workers health records
Area Toxic Gas
Monitoring

20. 2. Recognition of Health Hazards
d. Review of past Incident
investigation reports.
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e. Discussion with the
management and
workers

21. 2.1.Harmful Factors that exist at the
Workplace
Many workers may be exposed to a number of health hazards
at work.
Hazard recognition :
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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. (Refer to relevant Chemical Safety Data
Sheets)

22. 2.1. Health Hazards encountered at
Work
1. Chemical Substances
2. Physical agents.
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2. Physical agents.
3. Biological agents
4. Ergonomics
5. Psychological factors.

23. 2.1.1. Chemical Hazards
Hazards – risks are associated with the use of chemicals.
Hazardous chemicals may cause –
Fire & Explosion Forms of Chemicals
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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

24. 2.1.2. Physical Hazards
Excessive exposure to the following physical
hazards may cause harm to our health –
Noise
Vibration
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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

25. 2.1.3. 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,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 (Destroying Angel),
– Amanita phalloides (Death Cap)
Parasites Malaria, mites, leeches, intestinal worms
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26. 2.1.4. Ergonomic Hazards
Musculoskeletal disorders affecting workers may
arise from unsuitable work conditions or physical incapacity
to carry out their assigned tasks.
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1. Awkward body postures

27. 2.1.4. Ergonomic Hazards
Examples of unsuitable work conditions or physical incapacity:
2. Manual lifting of heavy loads
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3. Repetitive hand Movements

28. 2.1.4. Ergonomic Hazards
Examples of unsuitable work conditions or physical incapacity:
4. Cramp work space. 5. Poor lighting
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29. 2.1.5. Psychological hazards
Tensions at the workplace may disturb the
concentration and mental health of the worker
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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

30. 2.2. Workplace Inspection
Key considerations:
1. Inspection team members be knowledgeable on the process
and well versed in the aspects of worker safety and health.
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2. Inspection to be coordinated by a line supervisor.
3. Purpose of inspection - clearly defined and communicated to
each group member.
4. Method of inspection - agreed
5. All follow-up actions must be recorded and monitored.
6. Those at risk must be briefed on the actions that need to be
taken.

31. 2.2.1 Approaches in Workplace Observation
Geographical approach
– By location or work division
– Suitable to simple processes / various processes in the
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– Suitable to simple processes / various processes in the
same location
Hazard tracking
– Track specific hazards such as noise
– Used to evaluate compliance to specific Regulations.
Process flow
– By following the work activity or process
– Suitable for complex work processes

32. Identify all health hazards
– From both planned and unplanned activities
Communication with operators or workers
2.2.2. Workplace Observation
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Communication with operators or workers
who handle the process or control the
equipment
Measurement of hazard using equipment
– Direct reading equipment

33. Ask about symptoms/discomfort
– Example
Headache, skin irritation, vomiting
2.3. Employee Feedback
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– Headache, skin irritation, vomiting
Look into complaints
– Example
– No provision of Personal Protective Equipment

34. 2.4. Medical Records
Poisoning cases and work related diseases
Employee health complaints
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Health surveillance and occupational health
programs

35. To determine the level of worker exposure
(high, medium or low) to health hazards and the
effectiveness of the existing control measures,
3. Objectives of Risk Evaluation (Assessment)
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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.

36. 3.2. Risk Evaluation – what to look at?
3.2.1. Risk = Hazard x Exposure
Hazard Component
= Magnitude of hazard and the potential adverse health effects from
possible routes of entry or contact.
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= 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
3.2.2. Risk Conclusion – takes into account the work practices and
personal factors including individual susceptibility.

37. 3.2.1. (i) Characteristics of exposure
Who are exposed (based on Job types and tasks
3.2. Risk Evaluation
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Who are exposed (based on Job types and tasks
performed)?
How many are exposed?
What are they exposed to?
( 5 groups of health hazards)
How are they exposed?
Inhalation
Skin Absorption
Ingestion
Injection

38. 3.2.1. (ii) Level of Exposure
Frequency of exposure
– daily, weekly, monthly?
3.2. Risk Evaluation
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– daily, weekly, monthly?
Duration of exposure
– by seconds, minutes, hours?
Intensity of exposure
– high, medium, low?

39. 3.2.1. (ii) Level of Exposure
– Exposure intensity - Quantitative
Using equipment to measure the
3.2. Risk Evaluation
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Using equipment to measure the
intensity or magnitude of exposure
– Exposure intensity - Qualitative
Using observation and professional
opinion
Field Sling Psychrometer

40. 1. Chemical Substances
Consider the following factors when evaluating the risk of exposure
to chemicals hazardous to health:
Examples of Risk Evaluation
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to chemicals hazardous to health:
a) Work methods and practices
b) Work environment
c) Personal hygiene

41. 1. Chemical Substances
a) Work methods and practices
Observe each task to find out –
Examples of Risk Evaluation
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Observe each task to find out –
i. How chemical is being handled?
ii. Any chemical spillage?
iii. The use and maintenance of personal
protective equipment
iv. Any damage to skin or protective gear?
v. Duration of exposure to chemical

42. 1. Chemical Substances
b) Work Environment
i. Is the air being contaminated by chemical vapor, mist, dust or
fume?
Examples of Risk Evaluation
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fume?
ii. Any presence of pollutants on work surfaces?
iii. Any obvious smell? (Caution! Using senses to smell for
chemical odor is recommended.)
c) Personal Hygiene
i. Is PPE used clean before use?
ii. Has the worker washed hands with soap and water before
taking drinks or meals?
iii. Has worker showered at the workplace or at home, and
changed out the contaminated clothes with new, clean ones
(including the under garments)?

43. 3.2.2. Risk Conclusion
Risk conclusion is made after taking into account -
i. Level of risk exposure (high, medium or low) based on
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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

44. Levels of controls for exposure exceeding the
permissible limits need to be monitored to
ensure the protection of workers’ health.
Occupational Exposure Standards
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ensure the protection of workers’ health.
Permissible Exposure Limits (PEL)- Malaysia
Threshold Limit Value (TLV) - ACGIH
Workplace Exposure Standard (WES) – UK &
Australia

45. Permissible Exposure Limits (PEL)
under FMA 1967 (values in brackets – USECHH Reg2000)
LEAD : 0.15 mg/meter3 (0.05mg/m3 )
ASBESTOS : 1 fibre/millilitre air (0.1 fibre/ml of air)
NOISE
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NOISE
– 90 dBA for 8 hours; 115dBA maximum
– 140 dB for impulse noise
MINERAL DUST:
– 5 mg/m3 for respirable dust (3mg/m3 );
– 10 mg/m3 for total dust
– 0.1 mg/m3 for respirable quartz

46. CEILING LIMIT
– May not be exceeded at any time
8-HOUR TIME WEIGHTED AVERAGE (8-hour TWA)
Permissible Exposure Limits under
OSHA 1994(Malaysia)
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8-HOUR TIME WEIGHTED AVERAGE (8-hour TWA)
– May not be exceeded after average for a duration of 8 hours
MAXIMUM EXPOSURE LIMIT (15 MINUTE AVERAGE)
– May not be exceeded at any 15 minute average
– The value is three times the 8-hour TWA

47. Principle of Risk Control
Prioritise the control measures at the source, not the
worker
Prioritise the elimination of hazards, not the
4. Control of Health Risks
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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

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

49. 2.Prioritise the elimination of hazards, not
the reduction of exposure
No hazard means no exposure
Principle of Risk Control
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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

50. 3.Controls should target below the
permissible exposure limits
Principle of Risk Control
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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

51. 4.Controls should be as low as reasonably
practicable (ALARP), especially in cases where
there is no data on the permissible exposure limit
Principle of Risk Control
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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

52. 5.Use of personal protective equipment (PPE) as a
last resort
Successful use of PPE depends on worker cooperation and
Principle of Risk Control
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Successful use of PPE depends on worker cooperation and
training on proper use and maintenance of PPE.
To be effective, PPE needs to be worn at all times
Use of PPE is:
A temporary measure
An addition to other control measures
When other methods are not practicable

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

54. 1.Hazard Elimination
Prohibition of use
– Prohibition of the use of :
Hierarchy of Risk Controls
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Prohibition of the use of :
benzene as a grease remover
White phosphorus in the manufacturing of matches
Crocidolite (Blue asbestos) in all purposes except for
research or analytical purposes.
Ref: Occupational Safety and Health (Prohibition of Use
of Substances) Order 1999.

55. 2. Substitution
Substituting the hazard with a less
hazardous material/process
Hierarchy of Risk Controls
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hazardous material/process
Substitute benzene with xylene as a grease
cleaner.
Sand is substituted with glass beads in the
blasting and abrasive process

56. Hierarchy of Risk Controls
3. Isolation
Distance
Distance the hazard from the workers
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– Distance the hazard from the workers
Cover/Guard
– Cover the hazard
– Place guarding to prevent unwanted
entry/access to hazard

57. 4. Engineering Measures
Chemical
Methods of Risk Control
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– Ventilation, wet process
Noise
– Noise absorption, soundproofing, damping,
isolating vibration
Heat stress
– Automation, local temperature control

58. 5. Administrative Controls (Work Practices and Procedures)
Chemical
– Safe operating Procedures (SOP); limiting duration of
Methods of Risk Control
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Safe operating Procedures (SOP); limiting duration of
exposure
Noise
– Job rotation; scheduling of heavy machinery operations
Heat stress
– Hourly rests in cooler temperatures; increasing water intake;
acclimatisation

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

60. 6. Personal Protective Equipment
Head protection
Hands protection
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Respiratory protection
Hearing protection
Body protection (protective clothing)
Foot protection.

61. Unit 2 – Review Questions
1. What are the 2 key roles of Industrial Hygiene Practitioners?
2. Define the term Industrial Hygiene as given by the IOHA?
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3. What are the four basic principles of industrial hygiene?
4. List the various categories of Health Hazards?
5. In the risk evaluation process, what are the three factors that you would
consider to decide on your risk conclusion?
6. List the Hierarchy of Risk Controls?

62. Thank You.
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Thank You.