California Education Code § 17661(d)

Requires existing school facilities with HVAC systems to ensure that their "facilities, including, but not limited to, classrooms for students, have HVAC systems that meet the minimum ventilation rate requirements set forth in [the current state building code]…unless the existing HVAC system is not capable of safely and efficiently providing the minimum ventilation rate." Provides that if a school's existing HVAC system is not capable of meeting this standard, the school must ensure that the system meets the minimum ventilation rates in effect at system installation and must document the HVAC system's inability to meet the current ventilation standards in the annual HVAC inspection. Also requires schools to install MERV 13 filtration or higher if feasible; if not feasible, then schools must use the highest MERV level that the school determines is feasible. Also requires state agencies to develop and propose for adoption "mandatory standards for carbon dioxide monitors in classrooms."