California Hot Tub Safety Rules Mirror Pool Standards

Health and Safety Code section 115921 expressly defines spas and hot tubs as swimming pools when they hold water exceeding 18 inches in depth. Most residential hot tubs meet this definition and therefore must include at least two approved drowning-prevention safety features when newly installed or substantially modified after January 1, 2018. A locking, ASTM F1346-compliant safety cover is the most common qualifying feature for hot tubs. Public spas (those at hotels, gyms, or condominium common areas) are also regulated under H&S Code section 116025 et seq., requiring permits, water quality monitoring, and signage. State law preempts cities from adopting weaker standards.

Unpermitted public spas can be ordered closed. Residential hot tubs failing to include safety features may not pass final inspection. Negligence per se if drowning occurs.