Chemical Hazards & communication
Forms of chemical agent a) Dusts
– Solid particles suspended in air; fine & coarse
– Created by pulverizing, construction, furnace ash removal etc.
– Inhalable & Respirable Dust
b) Gases
– Substances above their boiling point
– Gets absorbed into blood when inhaled
c) Vapours
– Substances at or very close to boiling points
– Enters blood stream when inhaled
d) Liquids
– Substances at a temperature between freezing and boiling points
– Routes of entries are ingestion & absorption
e) Mists
– Similar to vapours but closer to liquid phase
– Produced by spraying
– Inhalation, ingestion, absorption
f) Fume
– Collection of very small condensed metallic particles of size < 1µm
– Generated by welding process
– Fall in the respirable range
g) Solids – Absorption or ingestion
Chemicals can change their physical form
Classification of hazardous substances
1. Health Hazard
Substance may be a carcinogen, can
damage eyes, lungs, or other target
organs; can also be a sensitizer,
mutagen, or be a respiratory
sensitizer.
E.g. Asbestos, tobacco smoke
Definition. A sensitizer & Mutagen
A sensitizer is defined by OSHA as "a chemical that causes a substantial proportion of exposed people or animals to develop an allergic reaction in normal tissue after repeated exposure to the chemical." The condition of being sensitized to a chemical is called chemical hypersensitivity
Mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level.
2. Acute Toxicity
The adverse effects of a
substance that result either
from a single exposure or
from multiple exposures
in a short space of time.
May be fatal or toxic.
3. Aquatic Toxicity
The effects of manufactured
chemicals and natural
materials and activities
on aquatic organisms
4. Oxidizing Agent
Strong oxidizers are capable
of forming explosive mixtures
when mixed with
E.g. Benzene
Explosive articles, and
substances as well as mixtures
and articles that are manufactured
to produce a practical explosive
or pyrotechnic
E.g. – Isocyanates, latex, wood dust
5. Explosives
6. Corrosive
Causes Skin Corrosion or Burns,
can cause eye damage and
Corrosive to metals.
Including compressed gasses,
liquefied gasses.
Gas released may be very cold.
Gas container may explode
if heated.
7. Gasses Under Pressure
8.Flammables
Flammable gasses, liquids,
or aerosols; self-reactive or
pyrophoric material;
self-heating substances and
mixtures, organic peroxides.
9. Irritant
Harmful to the skin or eyes,
a skin sensitizer or respiratory
irritant, may experience narcotic
effects