National Pesticide Information Center



Fipronil is a broad-spectrum insecticide in the phenylpyrazole chemical group. It acts on the nervous system by blocking the tiny gates on the nerve cell that control the sending of the nerve's signal. This causes the nerve to keep firing and eventually the nervous system stops working. Fipronil is used in agricultural and residential settings, including pet flea products.

General Questions about Fipronil

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Fact Sheet

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Precautions for Using Spot-on Flea and Tick Products

(2:38 min., 4.95MB)

If you have questions about fipronil, or any pesticide-related topic, please call NPIC at 1-800-858-7378 (8:00am - 12:00pm PST), or email at npic@ace.orst.edu.

Last updated March 16, 2012