How California OSHA’s Proposed Indoor Heat Illness Prevention Regulations May Affect Employers

• Once an indoor workplace exceeds the initial trigger of 82 degrees Fahrenheit (F), several provisions in the regulation are triggered.  

• If 87 degrees F or a heat index of 87 degrees F is reached, additional measures including acclimatization and ongoing measurements and controls are triggered.  

• The need to utilize what California OSHA terms as “clothing that restricts heat removal” lowers the trigger temperature for acclimatization, as well as ongoing measurement and controls, to 82 degrees F or a heat index of 82 degrees F. 

• In general, this regulation relies heavily on heat index measurements and limits rather than plain temperature measurements. 

• Accounts for both weather-related heat (in indoor workplaces without effective engineering controls in place) and process-generated radiant heat sources 

California OSHA is rolling out a separate indoor heat illness standard in addition to the outdoor heat illness prevention regulation that has been in place for several years. California is not the only state to have its own heat illness regulation. Washington, Minnesota, and Oregon now all have their own state specific heat illness prevention regulations in place, and Federal OSHA is promulgating a similar regulation. 

California’s outdoor heat illness regulation has been in emergency and then permanent form since 2005. Additional research into heat illness incidents associated with indoor work between 2010 and 2018 caused a resurgence in interest in developing a new indoor heat illness standard. 

There are some differences between the new indoor standard (Title 8, 3396, Heat Illness Prevention in Indoor Places of Employment) and the existing outdoor standard (Title 8, 3395, Heat Illness Prevention in Outdoor Places of Employment), and employers may require a bit of adjustment when trying to comply with the new standard.

For example, the current outdoor standard focuses on degrees Fahrenheit only, while the new proposed indoor standard references both temperature in degrees Fahrenheit as an initial trigger and then degrees Fahrenheit heat index further into the standard. Heat index takes humidity into account and is found using the temperature in degrees Fahrenheit along with the percentage of relative humidity, and by plotting the heat index on the National Weather Service heat index chart. It can also be measured using instruments that account for both temperature and humidity. From the chart below it is easy to see that even when the temperature is only 82 degrees F, depending on the humidity (75% or more) the heat index temperature can easily hit and exceed 87 degrees, pushing the workplace into the full requirements of this regulation.  

• Identifying and evaluating other environmental risk factors for heat illness 

• Keeping records of all measurements taken 

• Taking measurements during the time of greatest exposure 

• Taking measurements when it is suspected that measurements may be 10 degrees or more above the latest set of measurements 

• Retaining measurement records for 12 months or until the next set of measurements is taken, whichever is later 

• Using instruments that utilize the NWS heat index tables to measure heat index 

Section (e)(2) outlines engineering controls, administrative controls, and personal heat protective equipment in ranked order of preference. For example, if an employer wishes to bypass engineering controls in favor of administrative controls or personal heat-protective equipment, they must be able to establish the infeasibility of the higher-ranked engineering control. 

The emergency response section of the proposed standard is almost identical to the outdoor heat illness standard and requires effective communication with employees, supervisors, and emergency medical services. These plans will help to ensure an employee can be accessed by emergency medical providers, and that accurate directions to the workplace are given to emergency providers. The emergency response section also requires planning for and appropriate response to signs and symptoms of heat illness, including providing first aid and medical services and ensuring the affected employee is monitored and not left alone without being offered first aid or medical treatment as appropriate. 

Section (h) of the indoor heat illness regulation includes training topics for both employees and supervisors. These topics are identical to the training requirements found in the outdoor standard. However, allowances are made for the fact that shade is not a factor indoors and that weather monitoring may not play as large a role in some indoor workplaces. 

Water provision, including a specific volume per employee per hour and a requirement for the water to be suitably cool, is included in both standards. 

While shade is not a prominent topic in the indoor regulation, free access to a cool-down area is. Like in the outdoor regulation, employees must be allowed to access the area at all times, be monitored when in the area, encouraged to stay in the area, and not ordered back to work for at least five minutes and then only if all heat illness symptoms have abated.

The new indoor standard addresses acclimatization during heat waves by requiring close observation of employees if effective engineering controls for indoor temperatures are not in place. It also requires 14 days of close observation of newly assigned employees in workplaces where the indoor temperature or heat index equals or exceeds 87 degrees F or 82 degrees F in workplaces where employees must wear "clothing that restricts heat removal" or who work in high-radiant-heat areas. 

If the 82 Degree Fahrenheit Temperature Trigger Is Exceeded, Employers Will Need a Written Program