What does inflammability mean?
Inflammability is the measurable or qualitative tendency of a material to catch fire and continue burning. It is an important property in chemistry, manufacturing, construction, transportation, and workplace safety, where substances may be classified according to how readily they ignite and how rapidly they burn. The term is not identical to flammability, although the two words are closely related and often used interchangeably: inflammability is especially associated with technical, scientific, and regulatory writing, while flammability is more broadly used. Inflammability is distinct from inflammation, a medical term for the body's response to injury or infection. The word also differs from the related adjective inflammable, which is now avoided in some official contexts because it can be misread as meaning incapable of burning rather than exceptionally prone to catching fire.
nounThe degree to which a substance is capable of catching fire and burning readily. The term is especially used in chemistry, materials science, and safety assessments.
- The degree to which a substance readily catches fire and burns.
"The report identified the solvent's high inflammability as a significant handling risk."
"The coating was applied to reduce the wood's inflammability."
"Safety guidelines explain the inflammability of several cleaning products."
Fire-resistant materials are judged not merely by whether they burn, but by how readily they catch flame—an assessment known as inflammability.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does inflammability come from?
The word was formed in the 19th century from inflammable, with the suffix -ity added to create a noun meaning “the quality of being inflammable.” Inflammable itself comes through French from Latin inflammare, “to set on fire,” which was based on flamma, “flame” or “fire.” Its close relatives include inflammation, inflammatory, inflame, and flammable.
How inflammability is actually used
The term is formal and relatively uncommon in everyday speech; “flammability” is generally preferred in modern technical and regulatory language.
Easily confused with inflammability
Both terms describe how readily a material burns, but “flammability” is the more common general term, whereas “inflammability” is more characteristic of technical and safety contexts.
“Inflammability” concerns a material's tendency to ignite and burn, while “inflammation” is the body's response to injury or infection.