California Code, Penal Code - PEN § 17240

(a) As used in this part, “tear gas” applies to and includes any liquid, gaseous or solid substance intended to produce temporary physical discomfort or permanent injury through being vaporized or otherwise dispersed in the air.

(b) Notwithstanding subdivision (a), “tear gas” does not apply to, and does not include, any substance registered as an economic poison as provided in Chapter 2 (commencing with Section 12751) of Division 7 of the Food and Agricultural Code, provided that the substance is not intended to be used to produce discomfort or injury to human beings.