Bài giảng Ndustrial hygiene

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Chapter 2:
INDUSTRIAL HYGIENE 
Vietnam National University – HCMC
Ho Chi Minh City University of Technology
Faculty of Resource & Environment
Lecturer: Dr. TRAN BICH CHAU
Email: tbchau@hcmus.edu.vn
02/2016
1. What is Occupational/Industrial Hygiene?
2. Four steps to create healthy working place (A.R.E.C): 
– Anticipation
– Recognition
– Evaluation
– Control
3. Factors affecting to industrial hygiene: 
– Chemical hazards
– Physical agents
– Biological hazards
– Ergonomic hazards
OUTLINE: INDUSTRIAL HYGIENE 
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Industrial/Occupational Hygiene?
Interactions between people 
and the environment
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INDUSTRIAL HYGIENE
OCCUPATIONAL HYGIENE
= 0r ≠
What is the diferrence between industrial hygiene and 
occupational hygiene ???
Industrial hygiene is the science of anticipating,
recognizing, evaluating, and controlling workplace
conditions that may cause workers' injury or illness.
Berenice I. Ferrari Goelzer
What is Industrial Hygiene?
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What is Industrial Hygiene?
Industrial hygiene : the science of protecting
and enhancing the health and safety of
pepeole at work and in their communities.
The American Board of Inductrial Hygiene
Key factors:
- Employee exposure to hazards
- Control for hazards to protect workers
Basic principles of Industrial Hygiene
1. Anticipation of potential risks
2. Recognition of existing health hazards at the 
workplace
3. Evaluation of health risks
4. Contol of unacceptable risks
Remember the acronym: A.R.E.C
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Task planning and 
hazard analysis of 
injury/illness, trend 
analysis, reported 
concerns
Inspections, exposure 
assessment, modeling, 
visual assessments, 
professional judgment
Engineering controls, 
administrative 
controls, substitution, 
personal protective 
equipment
Review products, 
purchases, projects, 
tasks, designs, 
experiments, etc.
Steps to 
Protect 
Employees
Factors affected to industrial hygiene 
• Micro-climate
• Chemicals
• Noise
• Vibration
• Radiation
• Light
• Dust
• Harmful microorganism
• Ergonomic
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• Chemical hazards
• Physical hazards
• Biological hazards
• Ergonomic hazards
Factors affected to industrial hygiene 
Environmental Factors or Stresses
• gases, vapors, 
dusts, fumes, 
mists, and 
smoke
Chemical 
hazards
Physical hazards: 
radiation, noise, 
vibration, extreme 
temperatures and 
pressures
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Environmental Factors or Stresses
Hazards
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Chemical hazards
• Dusts, fumes, gases, mists
• Skin contact with oils, paints etc.
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Physical agents
• Noise, 
• Vibration
• Heat 
• UV
Biological hazards
• Legionella
• Zoonoses 
• Anthrax
Ex: Wastes from hospitals and
research facilities containing
disease-causing organism s that
could infect site personnel
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Ergonomic hazards
• Manual handling
• Repetitive work
• Display screen 
equipment
An ergonomic hazard is a physical factor within the 
environment that harms the musculoskeletal system
Factors affected to industrial hygiene 
• Micro-climate
• Chemicals
• Noise
• Vibration
• Radiation
• Light
• Dust
• Harmful microorganism
• Ergonomic
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Meteorology:
A microclimate is the distinctive climate of a small-
scale area, such as a garden, park, valley or part of a
city. The weather variables in a microclimate, such
as temperature, rainfall, wind or humidity, may be
subtly different to the condition prevailing over the
area as a whole and from those that might be
reasonably expected under certain types of pressure
or cloud cover
What is microclimate?
Occupational Hygiene:
Microclimate is the physical state of the atmosphere
in the narrow space of the workplace including the
factors temperature, humidity, radiant heat and speed
of air transport. These factors must be guaranteed in
certain limit, consistent with human physiology
What is microclimate?
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Classify of microclimate
Microclimate of working environment can be classified
into the following areas:
 Cold area;
 Thermally neutral microclimat, comfortalble, 
endurable areas;
 Warm or hot areas
Parameters of microclimate
Four basic parametere of thermal effect:
 Air temperature;
 Relative humidity;
 Air flow velocity ;
 Thermal radiation
Distinguising levels of climate sensation:
Comfortable levels
Endurable level
Unbearable level
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Temperature:
Temperature is the basic factor that acts on the
metabolism and human health. Temperature
may act directly or indirectly on human body
Temperature always transmits from hotter to
colder place by conduction, convection and
radiation.
Humidity:
- Humidity is the amount of water vapor in the
air.
- Higher humidity reduces the effectiveness of
sweating in cooling the body by reducing the
rate of evaporation of moisture from the skin.
 Vietnam Hygiene standard (TCVS
3733:2002): relative humidiy from 75 – 85 %
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Air flow :
- Flow of air into and out of a working area, ex:
an office space,
- It helps to dilute any contaminants by adding
some fresh air
- This can be provided by natural ventilation or
forced ventilation
Thermal radiation:
Thermal radiation is energy transfer by the emission of
electromagnetic waves which carry energy away from the
emitting object.
Examples of thermal radiation include the visible light
and infrared light emitted by an incandescent light bulb.
Infrared radiation - <760 nm (heat)
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Relationship of temperature, humidity and 
work performance:
The effects of microclimate factors to workers
List the effects of temperature and humidity to workers? 
Factors Effects
T0 high
T0 low
Humidity low
Humidity high
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Improvements of microclimate conditions
1. Technical measures
- Mechanization
- Manufacturing automation
- Ventilation 
- Air condition
- Thermal insulation
2. Administration and Medical Measures
- Set up reasonable schedules
- Provide enough PPEs
- Recruit/arrange suitable labors for each sector
- Supply enough nutritional food
- Perform periodic medical examinations
Improvements of microclimate conditions
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ERGONOMICS
WHAT IS ERGONOMICS”??
Ergos = work
Nomos = laws
Ergonomics = the laws of work
ERGONOMICS
What Does Ergonomics Mean?
 Designing jobs, equipments, and work tasks to fit 
human physical characteristics and energy 
limitations 
 It considers body dimensions, mobility, and the 
body’s stress behaviors
 “Make the work fit the person, not the person fit 
the work”
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Benefits of Ergonomics
– safer jobs with fewer injuries
– increased efficiency and productivity
– improved quality and fewer errors
– improved morales
Ergonomic Goals
 Reduce muscle and joint injuries -- and get the job 
done safely and quickly
 Keeping young/mature bodies from being worn out 
prematurely/early
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1. What’s he doing wrong ?
2. What are the wrong 
ergonomics that people 
usually have??
Wrong working postures
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Wrong working postures
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GUIDELINE ABOUT WEIGHTS
• Chemical hazards
• Physical hazards
• Biological hazards
• Ergonomic hazards
Factors affected to industrial hygiene 
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• Microclimate
• Argonomics
• Poisoning
• Noise
• Dust
Factors affected to industrial hygiene 
• A poison is any substance that can cause injury, 
illness or death when introduced into the body. 
• poisons are substances that cause disturbances in 
organisms, usually by chemical reaction or other 
activity on the molecular scale, when an organism 
absorbs a sufficient quantity
• Poisoning is considered a sudden illness
• The limit between non-toxic and toxic depends on 
doses. 
Poisoning prevention in industries
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Poisoning prevention in industries
Classify of toxic substance in industries
• Non-dangerous in contact and no health effect
• Harmful to health, but able to recovery
• Cause diseases and able to recovery
• Cause chronic diseases or death. 
Poisoning prevention in industries
• Factors causing harmful of a toxic
- Chemical characteristic
- Physical characteristic
- Exposure level/concentration and time
- Body condition, age, gender, biophysiology
of the receivors
- Environmental factors such as high humidity, 
high temperature, etc.
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 How poisons enter the body:
Injection
Inhalation
Ingestion
Absorption
respiratory tract
skin or eyes. 
skin
digestive tract 
Types of Hazards Toxicity
• Acute poisoning is characterized by
rapid absorption of the substance 
sudden & severe exposure.
• Normally, a single large dose/exposure is involved. 
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Types of Hazards Toxicity
• Chronic poisoning is characterized by prolonged or 
repeated exposures of a duration measured in days, 
months or years.
• Symptoms may not be immediately apparent, but tend 
to build up in the body. The effects are not seen until a 
critical body burden is reached.
• Normally, several small/little exposures are involved.
Symptoms of Poisoning 
 Nausea or vomiting.
 Diarrhea.
 Chest or abdominal pain.
 Trouble breathing.
 Sweating.
 Changes in consciousness.
 Seizures.
 Headache.
 Dizziness.
 Weakness.
 Irregular pupil size.
 Burning or tearing eyes.
 Abnormal skin color.
 Burn injuries around the 
lips or tongue.
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Care for Poisoning
 The severity of a poisoning depends on:
 The type and amount of poison.
 How and where the poison entered the body.
 The time elapsed since the poisoning.
 The victim’s size, weight, medical condition 
and age.
 Call 113, 114, 115 in Vietnam or the local 
emergency number for life-threatening emergencies 
first. 
Reasons for Poisoning in industries
The reasons of toxic contamination in productions
- Lack of knowledge about poisons
- Non-compliance procedures of poison uses and 
management
- Not use equipment for poisoning prevention
- Worker’s health is not good and workers have 
deseases that make their bodies increase 
susceptibility to poison 
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Reasons for Poisoning in industries
The reasons of toxic contamination in productions
- Old and out-of-date technologies applied in 
production cause toxic emission and contaminate the 
working environment 
- Poor ventilation
- Physical propeties of a poison
* lower evaporation abitity higher toxicity
* higher solubility in water and solvents 
higher toxicity
Technical solutions
- Eliminating toxins 
- Isolation and shielding
- Ventilation
- PPEs
- Fire fighting and protection
- Up-to-date technology
Poisoning prevention in industries
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Medical hygiene solutions
- Treating waste before disposal
- Perform periodic health examinations
- Personal hygiene
Poisoning prevention in industries
• Microclimate
• Argonomics
• Poisoning
• Dust
• Noise
Factors affected to industrial hygiene 
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Dust prevention in industries
Dust is the physical element with diffuse small size in 
air environment.
When in the air with toxic substances accounted for a 
large proportion, it will have an impact on human 
health: affect the respiratory system, vision and quality 
of life.
On human health: affect the respiratory system, vision 
and quality of life. 
Especially for inhalation, as small dust particles greater 
their impact, with a particle size of 0.5 - 10μm they can 
penetrate deep into the respiratory tract so called 
respiratory dust. 
Harm level of each substance depending on the nature 
of the dust, its concentrations in air, duration of human 
exposure, health status, size of dust particles
Effects of Dust 
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Dust prevention in industries
The smaller the size the more harmful. 
Large dust particles, the easier removal capabilities so 
little effects on humans.
Types of dust:
 organic 
 inorganic (more harmful)
Dust prevention in industries
Technical solutions
- Mechanization and automation of the production 
process dust to workers not exposed to dust and dirt less 
spread out.
- Changes in technology measures such as pneumatic 
transport, use a vacuum, clean with water instead of 
cleaning by sand blasting ...
- Sealed devices and production lines when needed.
- Change the dust generating materials with materials 
with little or no dust ...
- Use ventilation, vacuum in the dusty workshop
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Medical hygiene solutions
- Perform periodic health examinations
- Use PPEs : mask, protection cloths, glass, ect.
- Have a healthy eating plan: the rations for workers 
who work in dusty place need more vitamins, 
especially vitamin C. Provide plenty of vegetables 
and fresh fruits.
Dust prevention in industries
• Microclimate
• Argonomics
• Poisoning
• Dust
• Noise
Factors affected to industrial hygiene 
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Effects of Noise
- On human health: body collapse, diseases such as 
stress, anxiety, other indirect disorders, nervous 
system
- Lack of concentration on work, discomfort  
- Low quality of work.
What is the solution to prevent 
workers from noise????
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Summary: 
1. What is Occupational/Industrial Hygiene?
2. Four steps to create healthy working place (A.R.E.C): 
– Anticipation
– Recognition
– Evaluation
– Control
3. Factors affecting to industrial hygiene: 
– Chemical hazards
– Physical agents
– Biological hazards
– Ergonomic hazards