California Code, Health and Safety Code - HSC § 104559

(a) The use of tobacco and nicotine products is prohibited at any time in a county office of education, charter school or school district-owned or leased buildings, on school or district property, and in school or district vehicles. This includes, but is not limited to, smokeless tobacco, snuff, chew, clove cigarettes, and other nicotine delivery devices, such as electronic cigarettes.

(b) School districts, charter schools, and county offices of education shall prominently display signs at all entrances to school property stating “Tobacco use is prohibited.”