Cal. Penal Code § 641.5

(a) In any clothes cleaning establishment in which more than one gallon of a volatile, commercially moisture-free solvent of the chlorinated hydrocarbon type is used for dry cleaning, the performance of all the dry cleaning, drying, and deodorizing processes shall be completed entirely within fluid-tight machines or apparatus vented to the open air at a point not less than eight feet from any window or other opening and so used and operated as to prevent the escape of fumes, gases, or vapors into workrooms or workplaces. (b) Except when operations are performed as provided in subdivision (a), no person shall operate a clothes cleaning establishment in which more than one gallon of a volatile, commercially moisture-free solvent of the chlorinated hydrocarbon type is used for dry cleaning except under either of the following conditions: (1) All of the dry cleaning, drying, and deodorizing processes are performed in a single room or compartment designed and ventilated in such a manner that dangerous toxic concentrations of vapors will not accumulate in working areas. (2) The dry cleaning processes are performed in fluid-tight machines or apparatus designed, installed, and operated in a manner that will prevent the escape of dangerous toxic concentrations of vapors to the working areas. (c) “Volatile, commercially moisture-free solvent” means either of the following: (1) Any commercially moisture-free liquid, volatile product or substance having the capacity to evaporate and, during evaporation, to generate and emit a gas or vapor. (2) Any solvent commonly known to the clothes cleaning industry as a “chlorinated hydrocarbon solvent.” (d) Any violation of this section is a misdemeanor.