
(HazMat) Any material or substance, which even in normal use, poses a risk to health, safety, property or the environment. Hazardous materials are broken down into nine primary classes by the United Nations, the USDOT, IATA and other regulatory bodies for the purposes of the placarding and identification the hazards of shipments.
Found on
http://www.chemistry-dictionary.com/definition/hazardous+material+%28hazmat

A substance or material which the Department of Transportation has determined to be capable of posing a risk to health, safety, and property when stored or transported in commerce.
Found on
https://scmedu.org/hazardousmaterial/

Any material that poses a threat to human health and/or the environment. Hazardous materials are typically toxic, corrosive, ignitable, explosive, or chemically reactive.
Found on
https://www.encyclo.co.uk/local/22831
No exact match found.