HEALTH HAZARDS
&
INDUSTRIAL HYGIENE
BWU 10302 Occupational Safety & Health
Introduction to Occupational Health
• Started at the early period of Renaissance
middle ages
• Define by International Labour Organization
(ILO) as promotion and maintenance of
the physical, mental and social levels of
staff in all work sector
• Prevention from illnesses and diseases
due to the workplace or process, protection
from risk at work, and placement of
workers in environments and job task suitable
to their physiological and psychological
capabilities
• Increase quality of work environment and
work processes suitable to worker safety and
health conditions
Types of Prevention
The objective of occupational health service
 Identify and control hazards (provision of early treatment) and educate
both management and workers on the joint responsibility of ensuring and
safeguarding safety and health at work
 Promotion of healthy lifestyle programs such as health promotion and
education, exposure monitoring, health risk assessment, hazard control,
occupational fitness assessment and medical surveillance at least once a year
 Suiting the work and work environment to the worker, general medication
treatment, first and medical aid, disability assessment and data collection,
analysis and recordkeeping can be part of occupational health services
Organizations that related to occupational health and function description
in Malaysia: Department of Occupational Safety & Health (DOSH) : provides legislation, standards, enforcement and
promotion.
 National Institute of Occupational Safety & Health (NIOSH) : provides training, consultation, research and
information dissemination.
 Social Security Organization (SOCSO) : provides compensation and promotion.
 Ministry of Health Malaysia
Organization related to occupational health for international services: United Kingdom : Health Safety Executive (HSE)
 United State : National Institute of Occupational Safety & Health (NIOSH) & American Conference of
Industrial Hygienist (ACGIH)
 International Labour Organization (ILO)
 International Agency for Research into Cancer (IARC)
Epidemiology
• Is an introduction to human anatomy and physiology are important as
human body comprises many part and each part have its own function
• Determines the distribution and cause of disease
• Application of epidemiology such as: Clearly understand the causes of the various diseases
 Asses the level of harm and disease causing agent or material (e.g. benzene cause
cancer)
 Determine the Permissible Exposure Limit (PEL)
 Plan occupational safety and health programs.
Chemical hazards
• Chemical for which there is statistically significant evidence
(based on at least one study conducted according to
established scientific principles) that acute or chronic health
effects may occur in exposed employees.
• Substances that can cause harm or damage to the body,
property or the environment.
• Chemical hazards can be both natural or human made origin
Chemical Hazards
o Asbestos
o Mineral Dust
o Lead
Asbestos
• Asbestos is a generic name for magnesium silica that is formulated through the natural process
• Human can expose to asbestos through inhalation and ingestion
• Due to asbestos harmful ability, DOSH had been introduced two legislations which are Factories and
Machinery (Asbestos Process) Regulation 1986 and Occupational Safety and Health (Use and
Standards of Exposure of Chemicals Hazardous to Health) Regulation 2000
• Major occupations at risk due to asbestos process are factory workers for products using asbestos
and workers that are exposed to the use of asbestos materials such as shipbuilding, oil rigs etc.
• Due to asbestos hazard, control measures approach through elimination which prohibition of use
crociodolite. If eliminate possible, minimize exposure through work process and practice,
engineering controls and personal protective equipment. All expose workers should undergo health
surveillance program either by exposure monitoring, medical removal protection and medical
assessment by occupational health doctor (OHD). OHD will perform qualitative and quantitative
evaluation such as history (medical, occupational & smoking), clinical examination, chest x-ray and
lung function test.
Asbestos Health Effects
Mineral Dust
• Mineral dust specific characteristics
consist of 2 major elements which are
mineral dust and silica (Silicon dioxide).
• The mineral dust examples are silica,
kaolin, quartz etc.
• A method of mineral dust exposure is
through inhalation process.
• Occupations which at risk due to mineral
dust are mining, quarry, works
involving rocks containing silica and
boiling works (sand preparation &
sand blasting).
• Two related legislation in mineral dust activity which are Factories and Machinery
(Mineral Dust) Regulations 1989 and Occupational Safety and Health (Use
and Standards of Exposure of Chemicals Hazardous to Health) Regulations
2000.
• Health effect due to mineral dust is pneumoconiosis (fibrosis of the lung due to
inhalation of mineral dust), lung cancer, lung failure and risk of whooping
cough.
• Control measure of mineral dust by using elimination or substitution approach.
For example the used of local exhaust ventilation (LEV) or water spraying.
Other control measure is developing safe work procedure. Take care of cleanliness,
hygiene, changing room, cupboard and warning signage. Personal protective
equipment (PPE) such as respirator and clothing should be correct type, suitable,
good maintenance and hygiene.
Lead
• The specific characteristics of lead have two types which are non-organic lead and organic lead. The
non-organic lead used as metallic compound, alloy and chemical mixture. On the other side, organic
lead used as additives for internal combustion.
• Methods of lead exposure into human body are through inhalation and ingestion. The inhalation
process depends on particle size, particle dose, duration and frequency of exposure. Beside, ingestion
process depends on lack of personal hygiene work procedure and smoking while working.
• Related legislations in lead exposure are Factories and Machinery (Lead) Regulations 1984 and
Occupational Safety and Health (Use and Standards of Exposure of Chemicals Hazardous to
Health) Regulations 2000. These regulations stated about permissible exposure limit, risk
assessment, exposure monitoring, control measures and health surveillance.
• Some of occupations at risk to lead including car battery, plastic PVC(Pb – stabilizer), paint and
printing (Pb – pigment), glass making, cable and pipes lining.
• Due to lead hazardous occupation, health effect such as anemia, system reproduction (impotence &
miscarriage), kidney failure, high blood and nervous system (behavioral change & neuropathy)
cause chronic diseases.
Exposure Control Measures
Control Techniques
Explanation
Elimination /
Substitution
 Less hazardous material
Engineering
 Water spraying: vacuum
Administrative
 Information, instruction and training
 Changing room facilities, cleaning / laundry
and personal hygiene
 Isolated eating place, drinks and smoking
Personal Protective
Equipment (PPE)
 Respirator & clothing
 Type, suitability, good maintenance and
hygiene
Physical hazards
• Physical hazards are conditions or situations that can
cause the body physical harm or intense stress.
• Physical hazards can be both natural and human made
elements.
Physical Hazards
o Noise
o Radiation
o Vibration
Noise
• Defined as changes of pressure in the air, water and specific medium that
is identifiable by the human ear. Any unwanted sound is called noise.
• Sound components consist of frequency and amplitude or loudness of
sound. For layman term, frequency can be same as pitch (degree of highness
or lowness) and the unit is Hertz (Hz) or cycles per second.
• In other side, the unit for amplitude is decibel (dB). Sound level and their
sources determine by dB(A).
Sound Level and Their Sources
• Related legislation is Factories and Machinery (Noise Exposure) regulations 1989. Salient
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point in this regulation is permissible exposure limits, noise exposure monitoring, methods of
compliance such as engineering and administrative controls, audiometric testing, hearing
protection equipment, information, instructions and training as well as recordkeeping by the
employer.
This regulation also stated permissible exposure limit (PEL) for continuous noise for 8
hours is 90 dB(A) while the ceiling limit is 115 dB(A). Impulsive noise ceiling limit stated at
140 dB. Control measure should be implemented if the exposure exceed action level (AL)
which is 85 dB(A).
Occupations at risk are quarrying activities, mining activities, textile industry,
construction activities, carpentry activities and car manufacturing.
Some of health effects are including emotional disturbance and sensitive, communication
problems, loss of hearing, tinnitus, psychological disturbances and high blood
pressure.
Some control measures can be used are isolation of processes with high noise level,
minimize exposure (engineering controls, modification of work process & use of personal
protective equipment) and safe work practices. For health monitoring, it is compulsory to
undergo exposure monitoring conducted by a competent person.
Radiation
• Defined as emission and propagation of energy in the form of rays or waves. Energy radiated or
transmitted as rays, waves in the form of particles. A stream of particles or electromagnetic waves
which is emitted by the atoms and molecules of a radioactive substance as a result of nuclear.
• In industry, there are two types of radiation 1) ionized and 2) non-ionized. Source of ionized
radiation is from natural and artificial. The natural consist of cosmic, photon, neutron (particles –
alpha (α) & beta (β)), gamma (from earth & stone) and radon. Meanwhile, artificial ionized radiation
comprises medical procedures (radiology test), nuclear energy test and radioactive waste.
• Source of non-ionized radiation are ultraviolet (i.e; welding works), visible rays, laser, infrared (i.e;
metal manufacturing workers), microwaves and radio waves.
• Related legislations in radiation hazard stated in Atomic Energy Licenses Act 1984. Parts of
regulation are Radiation Protection (Licensing) Regulations 1986 and Radiation Protection
(Basic Safety Standards) Regulations 1988.
• Occupation at risk are welding activities, metal manufacturing, metal boiling / melting,
diagnostic radiology test workers, printing, communication and army. Besides that, medical
patient whom purpose of investigation and disease treatment can expose to radiation. Not to forget,
community will expose from natural sources.
Radiation Health Effect
Dependent
 Intensity of the
absorbed dose
 Types of radiation
(i.e; neutron and
alpha cells are more
dangerous than
photon x-rays)
 Organ sensitivities
(i.e; reproductive
tissues as more
sensitive than
thyroids)
Ionized Radiation
 Cancer
 Mutagenesis
 Central nervous
system syndrome
 Esophagus
 Damage to eyes
 Skin burns
 Loss of hair
 Infertility
 Mental retardness
and disabilities
among children
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Non-ionized
Radiation
Damage to eyes
(welding works)
Skin destruction (UV
and infra-red)
Skin burns (laser)
Heat stress (micro
waves)
• Three basic principles in control measures are justification, optimum protection and dosage level
(risk). As low as reasonably achievable concept consider time, distance and shielding the hazard. Hence,
make sure that the dosage level is not exceeding the permissible exposure limit. Radiation control measures
protection program are as below:-
 Risk assessment on new equipment
 Reduction of optimum exposure by time, distance and shielding – isolation guarding & engineering
controls
 Written standard operating procedures
 Training x-ray technician and radiation protection officer
 Maintain and observation
 Radiation safety audit
 Risk communication
• Health surveillance including exposure monitoring for individual (i.e; film badge) and workplace (i.e;
ionizing chamber) should be perform. Meanwhile, employee history (medical & occupational), clinical
assessment and medical transfer protection should be evaluated by medical officer.
Vibration
• Refers to the movement of solid objects where amplitude
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•
•
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and frequency produced causes harm to those exposed to
it.
Human organs have their own frequencies. When the
human body comes into contact with vibration, and the
frequency of the vibration is similar to the frequency for
an organ, the organ will also vibrate so called resonance.
Two types of vibration which are whole body vibration
(WBV) and hand arm vibration (HAV). The WBV is
usually transferred to the body via the buttocks or the
feet. Occupations at risk of WBV are ship workers and
drivers including lorries, buses and tractors.
Meanwhile, HAV is transferred through the hand via the
use of vibrating hand tools. Risk factor of HAV depend
on grip force, push force, duration, frequency of use,
posture and temperature.
Occupation at risk to HAV are workers who use vibrating
equipment such as grinder, electric saw, drills and
grass cutter machine.
• Related legislations stated in Occupational Safety & Health Act (OSHA) 1994 (General) referring
to objective 3: to promote a working environment that is conducive and suitable to the worker’s
psychological and physiological needs.
Vibration Health Effect
Whole Body Vibration
 Eye strain
 Nausea, vomiting, headache,
backaches
 May cause lung damage and
heart failure
Hand Arm Vibration
 Damages the peripheral blood
flow, periphery nerves and
musculoskeletal system
 Hand arm vibration syndrome
(paleness of fingers; aches and
pain in hands)
 Carpal tunnel syndrome
• Control measures of vibration hazard including conduct risk assessment
before purchasing vibrating equipment, hazard elimination through applied
automatic equipment or use of robot technology, hazard substitution
through selection of less vibrating machine or anti vibration equipment
and reduce duration of working time.
• Workers should done regular maintenance of equipment as well as
training, information and working instructions. Thus, exposure monitoring
using measurement of vibration magnitude (i.e; human vibration meter)
should be done to determine the quantity of vibration severity.
• Health surveillance objective assessment such as cold provocation test, grip
strength test and vibrotactile threshold test must be perform to acquire
health condition. History of medical, occupational, vibration exposure and
grading symptoms of vascular and sensory neural effect can be part of
health surveillance.
Biological hazards
• Biological hazards are biological agents / substances that
pose a threat to the health of living organisms, primarily
that of humans.
• These some biological agents can be viruses, parasites,
bacteria, food, fungi, and foreign toxins.
Biological Hazards
Identification of biological agents that causes Legionnaire’s
disease, Hepatitis B, HIV and E-bola are biological hazard.
Industries which expose to high biological risk are agriculture,
healthcare, biotechnology, research and clinical lab.
Definition of biological term
Term
Definition
Biological agent
Comprises living organisms such as virus, bacteria capable of
releasing toxic materials that can result in disease
Etiological agent
Agent that causes the actual disease
Infection
Attack by a pathogenic organism, whether resulting in disease or
not
Bio-safety
A field of science that tries to disconnect the elements in the
infection chain
Agent
Physical, radiological or chemical entity that may cause certain
effects upon exposure
Host
The habitat of the agent
Environment
Comprises living and non-living organisms (includes biosphere,
atmosphere, lithosphere, hydrosphere
The Interaction Between Agent, Host and
Environment
Infection Chain
• Factors for the onset of diseases
are including pathogenic agent,
existence of a reservoir, agent
capable of retention, agent
mobility, entry in new host and
susceptible host. Infection control
may be successful by breaking
one or more of the links in the
infection chain.
• Characteristics of biological agents have no threshold exposure limit, it can exist in
any environment, effected and influenced by biological competition make the
biological hazard very dangerous to human. Hence, safety precautions need to
determine when working with biological agents such as:
 Management of Bio-Safety Program
 Administrative controls
 Physical isolation
 Disinfection and sterilization
 Accident and emergency planning
 Transportation of biological agents
 Biological communication risk
Ergonomics Hazards
o History
o Purpose
o Risk Factors
History of Ergonomic
• The ergonomics itself means work or effort (ergon) and rules (nomos). This word first
used by Wojciech Jastrzebowski in the year 1857. It is a field of science that tries to
harmonies the system of work with human capacities.
Person
1. Frederick W. Taylor 
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2. Frank & Lillian
Gilbreth
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3. Ralph M. Barnes
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Knowledge Contribution
Seen as the Father of Modern Management
Discusses the methods of increasing efficiency of
workers
Focus on work productivity issues
Developed the Therbligs system to analyze
movements made during work tasks
Divided into two types of movements – efficient and
non-efficient
Continuation of the Gilbreth works with the
philosophy of economic movements to increase
productivity and reduce over exertion
Purpose of Ergonomic
• There have two major objectives of ergonomic: To increase levels of work efficiency and effectiveness or any related activity
undertaken such as through reduction of mistakes, increase of productivity and
simplification of tasks.
 To increase positive human values such as increased safety, reduce fatigue and
stress, increased work comfort ability and increased quality of work and life in
general.
• Based on the SOCSO statistics the number of reported cases for musculoskeletal
disorder (MSDs) increased every year. Hence, ergonomic hazard had been
identified the related legislation under third objective of OSHA 1994: to promote an
occupational environment for persons at work which is adapted to their physiological
and psychological needs.
Purpose of Ergonomic
• The best ergonomics approach is to fit the task to the worker rather than fit the
worker to the task.
• Purpose of ergonomics is to provide tolerable, acceptable and optimal work system.
Thus, the branches of ergonomics field separated into four parts which is
anthropometrics, biomechanics, physiology and psychology.
Ergonomic Risk Factors
• Factors that induce to musculoskeletal
disorder (MSDs) are doing repetitive
work, use of excessive force,
improper or static body posture, work
in long duration, vibration due to hand
tools and contact stress on the blood
veins, muscles and tendons due to
contact stress from hand tools or
equipment. A situation arising by
excessive use resulting in wear and tear to
muscles, tendons, joints and surrounding
tissues contribute to MSDs. Thus, in the
long term, it may result incapability to
use the related body part.
Ergonomic Risk Factors
Due to ergonomics hazard induce to human incapacity, job ergonomic analysis should
be perform based on the step below:
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Determination of measurement criteria and work target
Compilation of history for targeted job task
Identification of ergonomics risk factors
Discovery of preventive measures
Selection of preventive measures
Implementation of preventive measures
Monitoring of preventive measures.
Industrial Hygiene
o Overview
o Principle
o Risk Assessment
oRisk Control
Overview of Industrial Hygiene
• Defined as the 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.
• Industrial hygiene activities in Malaysia began in the 1970 when DOSH started to
conduct factory inspections to identify health hazards. Four regulations related to
the practice of Industrial Hygiene were gazette under the Factories & Machinery
Act (FMA) 1967.
• Regulations related to the practice of Industrial Hygiene were gazette under OSHA
1994. Role of Industrial Hygiene Practitioners are prevention of exposure to or
contact with health hazards and control of health risk in the workplace
environment.
Role of Industrial Hygiene Practitioner
Principle of Industrial Hygiene
• Anticipation of hazard, hazard identification, risk assessment and risk control of
chemical hazards, physical and biological agents from work activities with the
objective to prevent or reduce the risks to health.
• It is important to Industrial Hygiene practitioner to understand the hazard.
• Hazard is a source or a situation with a potential for harm in term of human
injury or ill health, damage to property, damage to the environment or a
combination of these.
• In general, health hazard consist 5 major elements which is chemical, physical,
biological and psychosocial and ergonomics.
Summary of Chemical, Physical and Biological
Hazards
Chemical Hazard
 General
 Dust, particles &
smoke
 Liquid & mists
 Gas & vapor
 Solvents
 Metals
 Acids & Bases
 Pesticides
Physical Hazard
 Noise
 Vibration
 Ionizing & nonionizing radiation
 Lighting
 Extreme high or
low temperature
 Extreme high or
low air pressure
Biological Hazard
 Micro organisms
 Bacteria & virus
 Insects
 Plants
 Fungus, yeast &
mold
Hazard Identification
• Hazard identification can be known through information source such as chemical inventory, chemical safety
data sheet (CSDS) and product specification. Others identification approaches are by process flow, factory
layout plan, observation or inspection, related feedback and medical records. This information on plant,
process and material is important to understand layout plan of machinery and equipment.
• Chemical inventory is including raw material, end product, by-product and waste. Also, process inventory such
as process flow, material used, conditions, standard operating procedures, potential hazards and control system
should be documented.
• Human resource department responsibility to provide employee information comprises of number of
employees and employee name list by department or unit based on gender, total working hours, work shift,
position and age.
• In several cases, information regarding on hazard can be determine through observation and inspection
(O&I). The objective of O&I is identification of hazards to health at the workplace and ensure that
occupational safety and health procedures are implemented. The workplace observation has three approaches:
Geographical, Hazard Tracking and Process Flow.
• From workplace observation, it’s able to identify health hazards from both planned and unplanned activities.
Hence, communicate with operators or workers who handle the process or control the equipment.
Measurement of unseen hazard severity by using direct reading equipment such as dosimeter for noisy
workplace.
Workplace Observation Approaches
Geographical
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By location or work 
division
Suitable
to
simple 
process or 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
Risk Assessment
• Objective of risk assessment is to enable decisions on the necessity of exposure controls and measures
and determine the level of exposure as well as its relationship to the risk of disease. An exposure
standard is the limit of worker exposure to a hazard without risk of adverse health effects. It is useful in
determining the necessity of risk control measures and permissible exposure limits (PEL). The element
of risk assessment as below:
 To know the properties of the hazard and its
risk to health
 Characteristics of exposure:
Who is exposed?
How many are exposed?
What are they exposed to?
How are they exposed? (inhalation, skin
absorption or ingestion)
Are there any existing control measures?
 Level of exposure
Frequency – daily, weekly or monthly?
Duration – by seconds, minutes or hours?
Intensity – high, medium or low?
 Analysis of results
• Level of exposure intensity consists of two parts which is quantitative and
qualitative.
• The quantitative method is using equipment to measure the intensity or
magnitude of exposure while qualitative method is using observation and
professional judgment. Quantitative assessment has two sampling techniques.
• For sampling strategy, the questions of why, what, who, when, duration and how
many sample should be determine before run the assessment. An assessment results
should be compare with exposure standards based on the rate of hazard or agent
production, its existence in the workplace and its level of absorption or contact as
well as sufficiency of control measures.
• Levels of controls for exposure exceeding the permissible limits need to be
monitored to ensure the protection of worker health such as permissible exposure
limits (PEL) and threshold limit value (TLV) in ACGIH.
Permissible Exposure Limits
FMA 1967
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Lead : 0.15 mg/meter3
Asbestos : 1 fiber/milliliter air
Noise :
90 dB(A) for 8 hours & 115 dB(A)
maximum
140 dB for impulsive noise
Mineral dust :
5 mg/m3 for respirable dust
10 mg/m3 for total dust
0.1 mg/m3 for respirable quartz
OSHA 1994
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Ceiling limit
May not be exceeded at any time
8 hour time weighted average (8h
TWA)
May not be exceeded after average
for a duration of 8 hours
Maximum exposure limit (15
minutes average)
May not be exceeded at any 15
minutes average
The value is three times the 8h
TWA
Risk Control
• The principle of risk control comprises priorities the control measures at the source, not the worker
and priorities the elimination of hazards, not the reduction of exposure. Controls should target below
the permissible exposure limits and as low as practicable, especially in cases where there is no data on
the permissible exposure limit. The use of personal protective equipment (PPE) as a last resort. The
hierarchy of risk controls is as bellow:
 Hazard elimination (Prohibition of use & employment of other methods)
 Substitution (Substituting the hazard with a less hazardous material or process
 Isolation (Distance & guard)
 Engineering control
 Administrative control (Work practices & procedures)
 Personal protective equipment
• As conclusion, the basis of occupational safety & health assessment is the identification of hazard,
risk assessment and risk control (HIRARC).