Seyfarth Synopsis: After a lengthy delay due in part to the COVID-19 pandemic, Cal/OSHA has published its proposed indoor heat illness prevention standard. After the publication, there is a 45-day comment period, ending at the Standards Board May 18, 2023 meeting. The Standards Board has one year from publication date to take action on the proposed standard.


For almost 20 years, Cal/OSHA has distinguished itself from Federal OSHA by, among other things, its heat illness prevention standard that applies to employers with employees working outdoors. Taking it up a notch, in 2016, SB 1167 was signed into law, which required Cal/OSHA to submit a proposal to the Standards Board on employee protection from indoor heat hazards. Thus began Cal/OSHA's work on an indoor heat illness prevention standard, starting first with several advisory meetings, and several draft standards. On April 22, 2019, Cal/OSHA published what was then its latest draft standard, which we blogged about previously. However the normally slow standards-making process was slowed down even more when the COVID-19 pandemic hit. Nothing has happened on Cal/OSHA's proposed indoor heat standard for the past few years. Until now...

What's Required Under The Proposed Standard

Key requirements of the proposed indoor heat standard are:

  • Applies to all indoor work areas where the temperature equals or exceeds 82 degrees Fahrenheit when employees are present.
  • Enhanced requirements for indoor work areas where the temperature or heat index equals or exceeds 87 degrees Fahrenheit when employees are present; employees wear clothes that restrict heat removal and temperature equals or exceeds 82 degrees Fahrenheit; or employees work in a high radiant heat area and the temperature equals or exceeds 82 degrees Fahrenheit. One such requirement is to measure and record the temperature or heat index (which is greater) in these hot areas where employees work, and implement various controls measures, for example engineering controls to reduce the temperature or heat index or both. In lieu of measuring and recording, an employer can opt to simply assume a work area is subject the enhanced requirements.
  • Allows compliance to be part of employer Injury Illness Prevention Programs, though employers can also choose to have a stand-alone written heat illness prevention program.
  • Employees must have access to fresh, pure, suitably cool, and free water as close as practicable to working areas and in cool down areas.
  • Employers must establish and maintain one or more cool down areas at all times, and encourage preventive cool-down breaks when employees feel the need.
  • Employers must use control measures to minimize the risk of heat illness, such as personal heat-protective equipment, administrative controls, and engineering controls.
  • Employers must have effective emergency response procedures.
  • Employers must have close monitoring of newly assigned employees and during a heat wave.
  • Employees must be trained on indoor heat illness prevention.

What's Next

The Standards Board has one year from publication date to take action on the proposed standard. The soonest the Board could adopt the standard is likely sometime in the summer or fall of 2023, though the regulatory process typically takes longer. While a formal codified heat illness standard may be months to (possibly) years away, California employers should keep in mind that in the absence of a heat illness standard, Cal/OSHA can and does enforce indoor heat hazards under the IIPP standard, under which employers must evaluate site-specific hazards at their workplace.

Workplace Solutions

Employers should stay on the lookout for updates to the indoor heat prevention rulemaking process, and in the interim, employers with hot indoor work areas should review their worksite hazard analyses and ensure that any indoor heat hazards are being controlled.

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