California Code, Health and Safety Code - HSC § 25210.2

(a) It is unlawful to sell or distribute in commerce a product that contains bronopol, dowicil, formalin, formaldehyde, glutaraldehyde, paraformaldehyde, para-dichlorobenzene, benzene, toluene, xylene, ethylene glycol, 1,1,1-trichloroethane, trichloroethylene, or perchloroethylene in a container that indicates that the product is suitable for use in a holding tank or other portion of a waste facility of a recreational vehicle.

(b) It is unlawful to use a product that contains bronopol, dowicil, formalin, formaldehyde, glutaraldehyde, paraformaldehyde, para-dichlorobenzene, benzene, toluene, xylene, ethylene glycol, 1,1,1-trichloroethane, trichloroethylene, or perchloroethylene in a holding tank or other portion of a waste facility of a recreational vehicle or of a campground chemical toilet that discharges to a septic system, onsite wastewater treatment system, or subsurface disposal system.

(c) To the extent that funding is made available, the State Water Resources Control Board shall investigate methods to detect and quantify concentrations of chemical toilet deodorants, including bronopol, dowicil, formalin, formaldehyde, glutaraldehyde, paraformaldehyde, para-dichlorobenzene, benzene, toluene, xylene, ethylene glycol, 1,1,1-trichloroethane, trichloroethylene, or perchloroethylene, in a septic system, onsite wastewater treatment system, or subsurface disposal system that may inhibit biological treatment processes or result in degradation of groundwater quality.

“The State of California prohibits the use of products in RV holding tanks, including deodorizers, that contain bronopol, dowicil, formalin, formaldehyde, glutaraldehyde, paraformaldehyde, para-dichlorobenzene, benzene, toluene, xylene, ethylene glycol, 1,1,1-trichloroethane, trichloroethylene, or perchloroethylene. These chemicals can inhibit biological activity in onsite wastewater treatment systems and threaten groundwater and drinking water wells, and are strictly forbidden.

Please use bacteria- or enzyme-based products.”

(e) Enforcement of subdivisions (a), (b), and (d) is contingent upon an appropriation by the Legislature for purposes of enforcing those requirements.

(f) This section shall become operative on January 1, 2022.