California Code of Regulations (Cal. Code Regs.): Title 24 – California Building Standards Code > Cal. Code Reg. §3120B.15 Gaseous oxidizer.
Where automatic gaseous chlorine chemical feeders are used, a warning sign with the appropriate hazard identification symbol shall be posted on the exterior side of the door entering the chemical feeder room or area. The sign shall state, “DANGER: GASEOUS OXIDIZER – (specific chemical name),” or as otherwise required by the California Fire Code.