As the temperatures cool outside, the regulations for indoor heat illness prevention are heating up. Cal/OSHA has been working on a proposed Indoor Heat Illness Prevention Standard since 2017. In the spring Cal/OSHA Standards Board published a draft standard and announced a public hearing on Heat Illness Prevention in Indoor Places of Employment.

On November 9, 2023, the Board issued its Second Notice of Proposed Modifications. These revisions were the result of further comments from stakeholders and Board staff.

Here are some of the proposed modifications:

• Clarifying that compliance is not required for incidental heat exposures where an employee is exposed to temperatures above 82 degrees for less than 15 minutes in any 60-minute period.
• Adds a definition for “high radiant heat source,” which is “any object, surface, or other source of radiant heat that, if not shielded, would raise the globe temperature of the cool-down area five degrees Fahrenheit or greater than the dry bulb temperature of the cool-down area.”  
• Adds detail that measuring temperature and heat index should be done where employees work and at times during the work shift when employee exposures are expected to be the greatest.  
• Clarifying that Indoor Heat Illness Prevention may be added to training pertaining to heat illness prevention for outdoor employment where employees are affected by both.

The Board is accepting written comments on the modifications of the text and the changes to documents until 5:00 p.m. on November 28, 2023, at the Occupational Safety and Health Standards Board, 2520 Venture Oaks Way, Suite 350, Sacramento, California 95833 or e-mailed to oshsb@dir.ca.gov.