The document discusses chemical hazards, defining them as substances that can cause harm, especially to people. It provides examples of common chemical hazards, how chemicals can enter the body, symptoms of chemical exposure, factors that influence chemical toxicity risk, effects of chemical hazards, and how to control chemical hazards through engineering controls, administrative controls, personal protective equipment, and using a combination of methods.

1. Chemical Hazard
Lecture on
Md. Abdullah-Al-Mahbub
 Assistant Professor
 Assistant Proctor
 Director, External Affairs (Former)
 Assistant Provost (Former)
Dept. of Disaster Management
Begum Rokeya University, Rangpur
Course code: 5203
Title: Disaster and Climate
Resilience, Occupational Health
and Safety

2. Q. What is the definition of chemical hazard?
Chemical Hazard
 A chemical hazard is any substance that can cause harm, primarily to people.
Chemicals of all kinds are stored in our homes and can result in serious injuries
if not properly handled.
 Any hazard that result from the accidental, deliberate or potential release of a
noxious substance into the environment.
 An element or mixture of elements or synthetic substances that are
considered harmful to people.
 A chemical hazard arises from contamination of an area with harmful or
potentially harmful chemicals.

3. Q. What is the definition of chemical hazard?
Chemical Hazard
 Possible sources of chemical hazards include:
• The burning of fossils, materials and chemicals used in construction and
industry, pollution of the environment and water supply, chemical
spillages, industrial accidents, and the deliberate release of toxic materials.
• Household cleaning products such as bleach, paints, acids, solvents
especially chemicals in an unlabelled container (warning sign!), it can
result in harmful chlorine gas or hydrochloric acid if carelessly used.
• Gases like acetylene, propane, carbon monoxide, helium and Gasoline
fumes from containers can result in major health hazards if inhaled.

4. Hazardous chemicals
Chemical Hazard
o Hazardous chemicals are substances that can cause adverse health effects
such as poisoning, breathing problems, skin rashes, allergic reactions, allergic
sensitisation, cancer, and other health problems from exposure.
o Many hazardous chemicals are also classified as dangerous goods. These can
cause fires, explosions, corrosion, and hazardous reactions if not handled
safely.

5. Hazardous chemicals
Chemical Hazard
o Examples of hazardous chemicals include:
paints
drugs
Cosmetics
 cleaning chemicals

6. Hazardous chemicals
Chemical Hazard
o Examples of hazardous chemicals include:
 refrigerant gases
 gas cylinders
 Degreasers (Safely dissolves grease and oils on most everything)

7. Hazardous chemicals
Chemical Hazard
o Examples of hazardous chemicals include:
 Pesticides
 herbicides

8. Hazardous chemicals
Chemical Hazard
o Examples of hazardous chemicals include:
corrosives
 welding fumes
 liquefied petroleum gas
 chemically reactive or acutely (highly) toxic substances.
 Petrol
 diesel fuel

9. Q. How do chemicals get into the body? or How do Chemicals Enter the Body?
Chemical Hazard
In order to cause health problems, chemicals must enter your body. There
are three main “routes of exposure,” or ways a chemical can get into your
body.
Four Routes of Entry:
1. Ingestion – swallowing the chemical
o Chemicals may be swallowed accidentally if food or cigarettes (or hands) are
contaminated.
o This can happen when chemicals have spilled or settled onto food, beverages,
cigarettes, beards, or hands.
o For this reason student and workers should not drink, eat, or smoke in areas
where they may be exposed to toxic chemicals.

10. Q. How do chemicals get into the body? or How do Chemicals Enter the Body?
Chemical Hazard
Four Routes of Entry:
2. Inhalation – breathing in the chemical
o Chemicals in the air are breathed in through the mouth or
nose.
o Gases & vapors are absorbed through the lungs directly into
the bloodstream.
o The size of dust particles or mist droplets can affect where
the chemical settles in the respiratory tract.

11. Q. How do chemicals get into the body? or How do Chemicals Enter the Body?
Chemical Hazard
Four Routes of Entry:
3. Absorption – the chemical soaks through the skin
o Some chemicals can pass through the skin into the body or
in the eyes.
o They can damage the skin, or be absorbed through the skin
into the bloodstream.
4. Injection-
o It can occur when a sharp object (needle) punctures the
skin and injects a chemical (or virus) directly into the
bloodstream.
Once chemicals have entered your body, some can move into your
bloodstream and reach internal “target” organs, such as the lungs, liver,
kidneys, or nervous system.

12. Q. What symptoms may be caused by chemicals at work?
Chemical Hazard
Organs Symptoms Common causes
Head Dizziness, headache Solvents, paint, ozone, smoke (including
tobacco)
Eyes Red, watery, irritated, grainy feeling Smoke, gases, various dusts, vapors from paint
and cleaners
Nose and
Throat
Sneezing, coughing, sore throat Smoke, ozone, solvents, various dusts, vapors
and fumes from paint and cleaners
Chest and
Lungs
Wheezing, coughing, shortness of
breath, lung cancer
Metal fumes, various dusts, smoke, solvents,
vapors from paint and cleaners
Stomach Nausea, vomiting, stomach ache,
diarrhea
Some metal fumes, solvents, paint vapors,
long-term lead exposure
Skin Redness, dryness, rash, itching, skin
cancer
Solvents, chromium, nickel, detergents and
cleaners, paint on skin
Nervous
System
Nervousness, irritability, sleeplessness,
tremors, loss of balance or coordination
Long-term solvent exposure, long-term lead
exposure
Reproductive
System
For men: low sperm count, damage to
sperm
For women: irregularities in
menstruation, miscarriage, damage to
egg or fetus
Lead, toluene, some other solvents, ethylene
oxide gas

13. Q. What are the factors that enhance your risk of chemical toxicity?
Chemical Hazard
1. How toxic the
chemical is
(toxicity).
The more toxic the chemical, the more likely it will cause health
problems, even in small amounts. Asbestos and cyanide are
considered highly toxic because a very small quantity can cause
health effects.
2. How the
chemical gets
into the
person’s body
(route of
exposure).
The way a chemical enters your body affects your risk. Some
chemicals, like the pesticide parathion, are very toxic whether they
get into the body through the skin, by breathing, or by swallowing.
On the other hand, asbestos is only harmful when inhaled or
swallowed. A house may have asbestos insulation, but unless the
asbestos is disturbed and becomes a dust in the air, it can’t be
breathed in, so it won’t cause harm.
3. The amount
of the chemical
that you are
exposed to
(dose).
For some chemicals, the higher the amount, the greater the damage.
For example, acetone is an industrial solvent that is also found in
nail polish remover. It is more dangerous to the worker who uses
large amounts than to the person who uses a little nail polish
remover.

14. Q. What are the factors that enhance your risk of chemical toxicity?
Chemical Hazard
4. How long you are exposed
to the chemical (duration).
The longer the exposure, the greater the danger. For example,
someone may work with a chemical for half an hour per day,
while another person is exposed for eight hours a day. Also,
someone may be exposed for one month, while another person
may have 20 years of exposure.
5. Reaction and interaction
with other chemicals.
Some chemicals in combination can create a different chemical
that is more hazardous than the original ones (reaction). For
example, ammonia and bleach used together can produce a
highly toxic chemical. Some chemicals, in combination, can
increase the likelihood of harm. For example, workers who have
been exposed to asbestos increase their likelihood of getting
lung cancer if they smoke cigarettes.
6. Individual differences (like
heredity, body size, age,
smoking, drinking,
allergies, sensitivities, or
previous exposures to other
toxic chemicals).
Chemicals can be more harmful to some people than to others.
Lead is much more harmful to small children than adults
because it affects their developing brain and nervous system. If
two people work with asbestos and one of them smokes, the
smoker is more likely to develop asbestos related lung cancer
than the non-smoker.

15. Q. List some effects of chemical hazards.
Chemical Hazard
Some of the health effects of exposure to hazardous chemicals include:
o skin irritation
o occupational asthma
o systemic chemical poisoning
o chemical burns from corrosives
o cancer.
About 47 000 persons die every year as a result of such poisoning. Many
of these poisonings occur in children and adolescents, are unintentional
(“accidental”), and can be prevented if chemicals were appropriately stored
and handled. Chronic, low-level exposure to various chemicals may result
in a number of adverse outcomes, including damage to the nervous and
immune systems, impairment of reproductive function and development,
cancer, and organ-specific damage. [source: World Health WHO]
Hundreds of millions of people in the developing world are regularly
exposed to potentially harmful indoor emissions, which are believed to
contribute to chronic lung disease, cancer, and ARI. [source: World Resources
Institute]

16. Q. How do you get information about hazardous chemicals?
Chemical Hazard
You can get information two ways:
1. from the product label,
2. from the product material safety data sheet.
Material safety data sheets or “MSDSs” are information sheets on products that:
o tells what chemicals are in the product,
o what the hazards of the chemicals are,
o how to protect yourself from the hazards.

17. Q. How do you protect yourself from hazardous chemicals?
Chemical Hazard
Protecting yourself from hazardous chemicals
1. Know what is in the product your work
2. Use the smallest amount of a chemical to do the job
3. Maintain machinery and equipment to prevent leaks or releases
4. Using available ventilation to reduce amounts of chemicals in the air,
5. Keeping lids, doors or covers closed on chemical processes
6. Wearing necessary personal protective equipment.
If you have been exposed to a chemical and feel sick:
o Let your instructor or supervisor know
o Find out what the chemical was
o Follow the first aid directions in the MSDS
o Get medical attention as needed
o Check your (PPE) Personal Protective equipment before going back to the area.
In the case of a leak or spill, protect yourself by:
o Informing your instructor or supervisor of unusual odors, spills, or releases
o By leaving an area of a large spill or chemical release

18. Q. How do you protect yourself from hazardous chemicals?
Chemical Hazard
Managing hazardous chemicals in the workplace
 Hazardous chemicals are substances that can harm people, property and the
environment. They include many common industrial, commercial, pharmaceutical,
agricultural and domestic chemicals.
 Hazardous chemicals must be treated as a risk in the workplace. This includes storing,
handling and managing them correctly to avoid harm to workers, members of the
public, property and the environment. You should:
o identify the hazardous chemicals in your workplace
o develop a risk management plan
o keep up to date with work health and safety codes of practice and legislation.
It's very important to put a risk management plan in place whenever employees or
employers are required to use, handle or store hazardous chemicals in the workplace.

19. Chemical Hazard
Q. How to control chemical hazards?
Controlling Chemical Hazards
Once chemical hazards are identified, various methods can be used to protect
workers from them. These are called hazard controls. Not all controls are equally
effective. There is a “hierarchy” of possible solutions. The most effective
solutions, at the top of the pyramid, are those that actually remove the hazard.
Further down are solutions that only reduce or limit the worker’s exposure.
Often a combination of methods is needed to get the best protection.

20. Chemical Hazard
1. Remove the Hazard
The best way to protect workers from hazards is to remove the hazards from
the workplace altogether, or at least keep them away from workers. These
methods are often called engineering controls. They directly address the
hazard and do not depend on workers’ actions to be effective. Workers don’t
have to wear special protective gear or take special precautions, because the
hazard is gone.
Engineering controls include these methods:
1. Redesign the process. For example: Replace gasoline motors with electric motors
to eliminate exhaust fumes.
2. Use wet methods when grinding, sanding, or using other tools to reduce dust
levels.
3. Substitute safer products for hazardous ones. For example, use chemicals that
are less toxic or dangerous, such as some water based cleaners.
4. Isolate the process, or isolate the worker from the process. For example, use
glove boxes when working with dangerous substances like radioactive material.
5. Install ventilation systems. These remove chemicals from the air that workers
breathe. The best systems remove vapors and fumes close to the source (local
exhaust ventilation).
Q. How to control chemical hazards?

21. Chemical Hazard
2. Improve work Policies and Procedures
When the hazard cannot be eliminated altogether, another option is to set rules
that will limit workers’ exposure to the danger. These measures are often called
administrative controls.
Administrative controls include:
1. Rotate workers between a hazardous task and a non-hazardous task so that the
length of exposure is reduced.
2. Increase the number of breaks to reduce the time of exposure.
3. Restrict access to the work area.
4. Improve personal hygiene facilities and practices. Provide a way for workers to
wash their hands and faces before eating and drinking. Prohibit eating in work
areas. Set up facilities for showering after the shift, and leaving contaminated
clothes at the workplace.
5. Provide worker training programs. Increase workers’ ability to recognize and
evaluate chemical hazards, and to take action to protect themselves.
Q. How to control chemical hazards?

22. Chemical Hazard
3. Provide Personal Protective Equipment
A third method of reducing hazards is to use personal protective equipment
(PPE). PPE is worn on the body and protects you from exposure to chemicals. It
includes gloves, goggles, respirators, and coveralls. Wear PPE when other
methods of hazard control aren’t possible or don’t give enough protection.
For PPE to be effective, workers must be given the correct PPE and trained in its
use, care, and storage.
PPE is usually considered less protective than the other methods because:
o It doesn’t get rid of the hazard itself. However, it can reduce the amount of
exposure by placing a barrier between the hazard and the worker.
o Workers may not want to wear it because it can be uncomfortable and hot,
and may make it hard to communicate.
o It has to fit properly to work. In many cases, it must be cleaned and
inspected often.
o It has to be the right type for the particular hazard, such as the right
respirator cartridge or glove for the chemical being used.
o Workers must know and remember how to use it properly.
o Some PPE creates its own hazards, such as heat, heavy weight, reduced
visibility and reduced hearing, restricted movement, and discomfort.
o PPE depends entirely on human action to be effective.
Q. How to control chemical hazards?

23. Chemical Hazard
Use a Combination of Methods
Sometimes you may need a combination of methods to control a chemical
hazard. While engineering controls may be the most effective method, you also
need to have training programs and good workplace policies to supplement
them. There may also be situations where PPE is essential. It’s important to
consider as many solutions as possible before settling on a strategy for
controlling chemical hazards.
Q. How to control chemical hazards?