Hazardous
materials ( HAZMAT )
The use of chemicals to enhance and improve life is a widespread practice worldwide . But alongside
the benefits of these products , there is the potential for adverse effects to
people or the environment
As a result a number of countries and organizations have
developed laws and regulations over the years that require information to be
prepared and be transmitted to those using chemicals , through labels or safety
data sheet ( SDS ).
Hazardous
materials or dangerous goods are solids , liquids , or gases that can harm
workers , the environment , and other living organisms , which include flammable
, radioactive , oxidizing , corrosive , explosive , Toxic , … etc
Dangerous
goods are divided into nine classes ( in addition to subcategories ) :
Class 1 ـــــ Explosives
Class 2 ـــــ Gases
Class 3 ـــــFlammable liquids
Class 4 ـــــ Flammable solids
Class 5 ـــــOxidizer
Class 6 ـــــ Toxic
Class 7 ـــــ Radioactive
Class 8 ـــــ Corrosive
Class 9 ـــــ Miscellaneous
Class 1 ــــ Explosives
The United States Department of Transportation (DOT) regulates hazmat
transportation within the territory of the US.
1.1 — Explosives with a mass explosion hazard. (nitroglycerin/dynamite)
1.2 — Explosives with a blast/projection hazard.
1.3 — Explosives with a minor blast hazard. (rocket propellant, display
fireworks)
1.4 — Explosives with a major fire hazard. (consumer fireworks, ammunition)
1.5 — Blasting agents.
1.6 — Extremely insensitive explosives.
Class 2 ـــ Gases
2.1 Flammable Gas: Gases which ignite on
contact with an ignition source, such as acetylene, hydrogen, and
propane.
2.2 Non-Flammable Gases: Gases which are
neither flammable nor poisonous. Includes the cryogenic gases/liquids (temperatures
of below -100 °C) used for cryopreservation and rocket fuels, such as nitrogen,
neon, and carbon dioxide.
2.3 Poisonous Gases: Gases liable to cause death
or serious injury to human health if inhaled; examples are fluorine, chlorine,
and hydrogen cyanide.
Class 3 ـــ flammable liquids
Liquids which can burn and have a Flash Point (not boiling point)
below 60.5°C
Class 4 ــ flammable
solid
4.1 Flammable
solids e.g. phosphorous (red).
4.2 Substances liable to (white) spontaneous combustion e.g.
phosphorus.
4.3 Substances which, when they come in contact, emit flammable
gases e.g. sodium with water.
Class 5 ــ Oxidizer
5.1 Oxidizing agents e.g. ammonium dichromate.
5.2 Organic peroxides e.g. ethyl methyl ketone peroxide.
Class 6 ــToxic
Class 6 is sub-divided into the following two Divisions:
6.1 Toxic substances e.g. cyanides, arsenic compounds and lead acetate.
6.2 Infectious substances: Infectious
substances are substances which are known or are reasonably expected to contain
pathogens. Pathogens are defined as micro-organisms ( including bacteria,
viruses, rickettsiae , parasites, fungi ) and other agens such as prions, which
can cause disease in humans or animals
Class 7 ـــ Radioactive
Substances and articles which spontaneously emit
radiation greater than 70 kilobequerals per kilogram e.g. uranium oxide.
Class 8 ــ corrosives
Corrosive substances are substances that can dissolve organic tissue or
severely corrode certain metals Acids and alkalis eg. sulfuric acid, hydrochloric acid , sodium hydroxide
Class 9 ــ Miscellaneous
Dangerous substances and articles that do not fit into the above
categories. asbestos,
air-bag inflators, self inflating life rafts, dry ice
Many Dangerous
Goods present the hazards of more than one Class or Division. Such goods are
assigned to a Class according to their primary hazard. The other hazard or
hazards are referred to as Subsidiary Risks.
Examples:
- Methanol is a highly flammable liquid that is also toxic. It meets
the classification criteria for both Class 3 and Division 6.1. As its
flammability is its primary hazard, Methanol is assigned to Class 3. It is also
shown in the Australian Dangerous Goods Code as having a Subsidiary Risk of 6.1
to cover its toxicity hazard.
- Nitric Acid, Red, Fuming is corrosive, a strong oxidising agent
and toxic. It meets the classification criteria for Classes 8, 5.1 and 6.1. As
its corrosivity is its primary hazard, Nitric Acid, Red, Fuming is assigned to
Class 8. However, it is also allocated Subsidiary Risks of 5.1 and 6.1 to cover
the other hazards.
