Dangerously Reactive Materials
Dangerously Reactive Materials are unstable or highly
reactive materials that can undergo extremely hazardous
uncontrolled reactions.They can cause explosions,
fires or extreme heating, with potential for
significant personal injury and property damage.
These materials are not commonly used in
workplaces because of their hazards.When used,
they must be handled and stored in stringently
controlled conditions. Specialized training and
supervision is required.
Hazards of Dangerously Reactive Materials
This WHMIS Class covers various dangerous reactions
Decomposition – an unstable chemical breaks apart into
simpler chemicals, e.g. nitroglycerin
Polymerization – a chemical reaction in which many small
molecules (monomers) join together to form a large chain-
like molecule (polymer), e.g. acrylonitrile, acrylates
Reaction with water to release a toxic gas, e.g. chlorosulfuric
Self-reaction when shocked or heated, e.g. metal azides
in automobile airbags
In many cases the dangerous reaction can be controlled by
adding a stabilizer or inhibitor. This is a chemical that is
added in small amounts to the material to slow down or
prevent an unwanted reaction such as polymerization.
Many dangerously reactive materials are also highly reactive
with many other incompatible materials.
Many of these materials also possess other hazardous properties.
For example, Methyl ethyl ketone peroxide is also oxidizing
(WHMIS Class C), very toxic (Class D1A), and corrosive
Working Safely with Dangerously Reactive
Dangerously reactive materials require extreme caution
during handling and storage because of the ease with which
a hazardous reaction can start.You must know about conditions
that could lead to instability or reactions [see the Stability
and Reactivity section of the Material Safety Data Sheet
(MSDS)] and make sure that they never occur.
UNDERSTAND all of the hazards (e.g. toxicity, corrosivity,
flammability) associated with the material