California’s Division of Occupational Safety and Health has released sweeping draft revisions to both its indoor and outdoor heat illness prevention regulations, signalling significant change for employers statewide.
The draft proposals, posted online by Cal/OSHA, cover changes to the outdoor heat illness prevention regulation under Title 8, California Code of Regulations Section 3395, and the indoor equivalent under Section 3396.
The regulatory push stems from Assembly Bill 2243, signed by Governor Newsom at the conclusion of the 2021-22 legislative session, which directed Cal/OSHA to strengthen protections for outdoor workers.
AB 2243 originally proposed an “ultrahigh heat” standard but was ultimately revised to focus on two primary objectives: updating acclimatization requirements and addressing the distribution of Heat Illness Prevention Plans.
Notably, Cal/OSHA’s draft revisions go beyond the scope of AB 2243, which only directed the agency to update outdoor requirements under Section 3395, by also proposing changes to indoor standards under Section 3396.
The revisions to the outdoor heat illness regulation provide greater detail and stronger requirements around acclimatization, with the same substantive changes mirrored in the indoor heat illness prevention regulation.
Under the proposed rules, employers would be required to distribute their Heat Illness Prevention Plans to new employees upon hire, during heat illness prevention training, and at least once a year to every covered employee.
The draft language does include a cap on mandatory distribution, limiting the requirement to no more than twice annually per employee, offering employers some practical flexibility in compliance planning.
Cal/OSHA simultaneously released a draft revision to its wildfire smoke regulation, which would adjust the Air Quality Index table so that a PM2.5 reading of 301 or above is categorised as “hazardous,” rather than the previous range of 301 to 500.
The agency announced that future advisory committee meetings would be scheduled to discuss the proposals further, and Cal/OSHA requested that written comments on the draft regulations be submitted by 7 July 2025.
Employers across California with outdoor workforces, including those in agriculture, construction, and logistics, will need to closely monitor these developments as the rulemaking process advances.
The dual focus on both indoor and outdoor environments reflects growing recognition that heat illness risk is not confined to outdoor settings, with warehouses and other indoor workplaces presenting serious hazards during extreme heat events.