Harmful chemical compounds in the form of solids, liquids, gases, mists, dusts,
fumes, and vapors exert toxic effects by inhalation (breathing), absorption (through
direct contact with the skin), or ingestion (eating or drinking).
Airborne chemical hazards exist as concentrations of mists, vapors, gases, fumes,
S t i th h i h l ti d f th i it t th ki t tSome are toxic through inhalation and some of them irritate the skin on contact;
some can be toxic by absorption through the skin or through ingestion, and some
are corrosive to living tissue.
The degree of worker risk from exposure to any given substance depends on the
nature and potency of the toxic effects and the magnitude and duration of exposure.
A Chemical May Be:y
A physical hazardA physical hazard
- a chemical is a physical hazard if it has the potential for fire,
explosion or reactivity
A health hazard
Both a physical hazard and a health hazard
Neither a physical or health hazard
Example of chemicals:
• Liquids (diesel fuel)q ( )
• Solids (coal or silica dust, welding fumes)
• Gases (NO2 from blasting
Main Substances Categories
Produces acute or chronic effects in exposed workers
• Carcinogen - Carcinogenic Substances which cause cancer in various
body organs, for example: skin cancer - waste oils, tar, cancer of the
upper respiratory system – wood dust, particularly hard woods, lung
cancer - asbestos, rubber fume, liver cancer - vinyl chloride
• Toxic Agent - poisonous / cause acute or chronic effects
• Reproductive toxin (teratogen) - could have harmful effect on maleReproductive toxin (teratogen) could have harmful effect on male
or female reproductive system or on developing fetus
• Irritant - Irritant Substances which on contact, react with the body’s
tissues e g causing inflammation: sore itchy eyes stuffy nosetissues, e.g causing inflammation: sore, itchy eyes, stuffy nose,
coughing and sneezing, blotchy red Skin
• Corrosive - cause irreversible damage to living tissue
Sensitizer cause exposed person to develop allergies to the• Sensitizer - cause exposed person to develop allergies to the
• Target organ-specific agents - hazardous to specific organs in body
( l li bl d kid t )(e.g., lungs, liver, blood, kidneys, nervous system)
Route of Entryy
For a chemical to have an effect on a worker, s/he must
be exposed to it and some
• Inhalation / breathing - most common route, gases / vapors
can pass to blood, solid particles inhaled into lungs
• Absorption through the skin - many solids, liquids, vapors and
gases can be absorbed through the skingases can be absorbed through the skin
• Ingestion / swallowing - while not intentional, failure to wash
hands, eating in contaminated lab, etc.
• Injection - accidents handling glass, sharps, etc.
• Eye Contact - either physical damage or absorption
The route of entry dictates selection of
Chemical Poisoning Symptonsg y p
• There are several symptoms of chemical
poisoning whether by swallowing, touching
– Difficulty breathing
Headache or blurred vision– Headache or blurred vision
– Irritated eyes, skin, throat
Ch i ki l– Changes in skin color
– Unusual behavior
– Clumsiness or lack of coordination
– Stomach cramps or diarrhea
Work EnvironmentWork Environment
B f t t k d tBefore we start work we need to:
• Identify the substances, products
• Recognise the warning labels
• Interpret the data from vendor data sheets• Interpret the data from vendor data sheets
• Interpret the data from laboratory reports
• Identify the potential exposure
• Ask yourself “if its hazardous do I need toy
• Describe the task to be undertaken
Id tif th b t t b t t d d• Identify the substance to be contacted or used
• Identify the approximate volume of likely exposure
• Re-visit the above and ask the following.
• Do we need to do this task?
• Do we need to use this product?
• Is there a safer (personal & environmental) product
il bl ?available?
• Do we need to set in place specific engineering controls?
D d i k h l h?• Do we need to monitor our workers health?
• Do we need to have specialist training or vendors?
• Information on the risk to workers from chemical hazards can be obtained from the
Material Safety Data Sheet (MSDS).
The MSDS is a summary of the important health, safety, and toxicological information
on the chemical or the mixture's ingredients. Other provisions of the Hazard
Communication Standard require that all containers of hazardous substances in theCommunication Standard require that all containers of hazardous substances in the
workplace have appropriate warning and identification labels
• MSDS explains the following:–
– Identity of the chemical–names, manufacturer, compositionIdentity of the chemical names, manufacturer, composition
– Physical & chemical characteristics–density, bpt, flash point, appearance,
odour, melting point
– Physical hazard‐fire & explosion and how to combat themy p
– Health hazard–reveals if carcinogenic and exposure limits
– How the chemical enters the body–ingestion, inhalation, skin, eye
– Reactivity–situations that makes the chemical unstabley
– PPE–recommended PPE to prevent exposure
– Spills, leaks & disposal–what to do in the event of leak and how to dispose
– Handling & storage–proper way to handle and store the chemical
Personal Protective Equipmentq p
Personal Protective Equipment
This is your line of defence• This is your line of defence.
• You have asked all the relevant questions
• You have made the risk to you and others
A L A R PAS.LOW.AS.REASONABLE.PRACTICABLE
• Know the risk of chemicals
– Know where to find specific risks
– Know proper protective equipment for each riskKnow proper protective equipment for each risk
– Know emergency procedures
Know compatibilities– Know compatibilities
– Know correct disposal