pyrophoric

American  

[pahy-ruh-fawr-ik, -for-] / ˌpaɪ rəˈfɔr ɪk, -ˈfɒr- /

adjective

Chemistry.

1. capable of igniting spontaneously in air.

---

pyrophoric British  

/ ˌpaɪrəʊˈfɒrɪk /

adjective

1. (of a chemical) igniting spontaneously on contact with air

2. (of an alloy) producing sparks when struck or scraped

   lighter flints are made of pyrophoric alloy

---

Etymology

Origin of pyrophoric

1780–90; < Greek pyrophór ( os ) fire-bearing ( pyro-, -phorous ) + -ic

Example Sentences

Defense Department has placed significantly fewer orders for Alloy Surfaces’ pyrophoric airborne decoys, which the company manufactures in Philadelphia and are used as protection against heat-seeking missiles.

From The Wall Street Journal

George Koutsantonis, a chemist at the UWA, describes her components as “vital” for his research on pyrophoric chemicals, which ignite spontaneously if exposed to air.

From Nature

Static or piezoelectricity is another popular candidate for the helicopter halos–as opposed to the pyrophoric, muffler-scraping-on-the-road phenomenon I describe in the video above.

From Scientific American

But again, if the helicopter blades aren’t pyrophoric but do conduct electricity, the whole effect disappears.

From Scientific American

Prosecutors say the fire broke out when Sangji, a recent college graduate who had only been working in the lab for some 2 1/2 months, was performing an experiment with tert-Butyllithium, a pyrophoric chemical, meaning that it spontaneously ignites when exposed to air.

From Reuters