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Periodic Graphics

Periodic Graphics: Suppressing wildfires with chemistry

Chemical educator and Compound Interest blogger Andy Brunning answers questions about Phos-Chek, a fire retardant used to stop forest blazes

by Andy Brunning
November 24, 2019 | A version of this story appeared in Volume 97, Issue 46


This infographic describes the fire retardant Phos-Chek, which is being used to fight wildfires in California and elsewhere. It shows an image of a plane spreading red Phos-Chek over a forest at the top center of the graphic. And it shows chemical formulas of ammonium phosphate and sulfate.
Credit: Andy Brunning/C&EN; Shutterstock (photo)

To download a PDF of this article, visit

References used to create this graphic:

Hogue, Cheryl. Seeing Red Chem. Eng. News, Aug. 29, 2011.

Kalabokidis, K. D. Effects of wildfire suppression chemicals on people and the environment Global NEST J. (July 2000). DOI: 10.30955/gnj.000144.

Kishore, Kaushal, and Kottotil Mohandas. Mechanistic Studies on the Action of Ammonium Phosphate on Polymer Fire Retardancy Combust. Flame (1981). DOI: 10.1016/0010-2180(81)90013-4.

US Forest Service. Phos-Chek Fire Retardants for Use in Preventing and Controlling Fires in Wildland Fuels Accessed Nov. 15, 2019.

A collaboration between C&EN and Andy Brunning, author of the popular graphics blog Compound Interest

To see more of Brunning’s work, go to To see all of C&EN’s Periodic Graphics, visit



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