Audit, Compliance and Risk Blog

On August 30, the Occupational Safety and Health Administration (OSHA) published its proposal to adopt a new Heat Injury and Illness Prevention Standard (29 CFR 1910.148) covering most OSHA-regulated employers. This rulemaking expands OSHA’s ongoing efforts to protect workers against heat hazards; previously, the agency has emphasized that known heat hazards trigger the Employer’s General Duty Clause (I wrote about OSHA’s National Emphasis Program for both outdoor and indoor workplaces HERE ).  

What situations does the new standard cover? 

How hot is dangerously hot? Workers in a hot environment must shed excess heat to maintain a stable internal temperature, by circulating blood to the skin, and by sweating. These become less effective when the air is close to or warmer than normal body temperature, and/or when high humidity prevents effective evaporation. Even when self-cooling works, the workers’ bodies tend to heat up, while fluids and salts are lost by sweating.  

Safety professionals apply temperature and humidity to evaluate the heat effects on exposed individuals. OSHA is proposing to set two successive “heat triggers” that will require the employer actions described below: 

• initial heat trigger – temperature at least National Weather Service (NWS) heat index of 80 degrees Fahrenheit (°F), or a wet bulb temperature equal to the National Institute for Occupational Safety and Health (NIOSH) Recommended [Heat Stress] Alert Limit. 

• high heat trigger - temperature at least NWS heat index of 90oF, or a wet bulb temperature equal to the NIOSH Recommended [Heat Stress] Alert Limit. 

The requirements apply in indoor and outdoor locations, which the proposal distinguishes as follows: 

• “Indoor/indoors means an area under a ceiling or overhead covering that restricts airflow and has along its entire perimeter walls, doors, windows, dividers, or other physical barriers that restrict airflow, whether open or closed.” 

• “Outdoor/outdoors means an area that is not indoors. For purposes of this standard, vehicles operated outdoors are considered outdoor work areas unless exempted [in situations specified below].” 

The proposed rules would not apply to the following situations: 

• work activities with no reasonable expectation of exposure at or above the initial heat trigger 

• short duration employee exposures at or above the initial heat trigger for 15 minutes or less in any 60-minute period 

• organizations whose primary function is firefighting; emergency response activities of workplace emergency response teams, emergency medical services, or technical search and rescue; and any emergency response activities already covered under specified OSHA standards 

• work activities performed in indoor work areas or vehicles where air conditioning consistently keeps ambient temperature below 80°F 

• telework (i.e., from home or another remote location of the employee’s choosing) 

• sedentary work activities at indoor work areas that only involve some combination of the following: sitting, occasional standing and walking for brief periods of time, and occasional lifting of objects weighing less than 10 pounds 

Employers that only employ employees in exempt activities would be exempt. 

What compliance requirements apply? 

The new standard requires covered employers to do the following: 

Heat Injury and Illness Prevention Plan (HIIPP)

Employers must develop HIIPPs, which must include the following, on a site-specific basis: 

• comprehensive list of the types of work activities covered by the plan 

• all policies and procedures necessary to comply with the standard 

• identification of the heat metric (i.e., heat index or wet bulb globe temperature) the employer will monitor to identify heat hazards 

• if any employees wear vapor-impermeable clothing, evaluation of associated heat stresses, along with policies and procedures “based on reputable sources” to protect employees wearing such clothing 

• be in writing, if the employer has more than 10 employees 

• designate one or more heat safety coordinators to implement and monitor the HIIPP, with authority to ensure compliances, and document their identity(ies) in any written HIIPP 

• provide for input and involvement of non-managerial employees and their representatives in development and implementation of the HIIPP 

• review and evaluate the effectiveness of the HIIPP annually, and after any heat-related illness of injury that results in death, days away from work, medical treatment beyond first aid, or loss of consciousness; update the HIIPP as necessary 

• make the HIIPP readily available at the work site to all employees (i.e, not just those assigned to relevant locations and activities) 

• make the HIIPP available in a language that each employee, supervisor and heat safety coordinator understands 
  

Heat hazard identification and monitoring

The proposal directs employers to assess outdoor and indoor heat hazards, as follows: 

• outdoor work  

• • employer must monitor heat conditions, by tracking local heat index forecasts from NWS or other agencies, or directly measuring heat index, or temperature and humidity or wet-bulb temperature as close as possible to the work area(s) 

• • monitoring must be frequent enough to “determine with reasonable accuracy employees’ exposure to heat” 

• indoor work 

• • employer must identify each work area with a “reasonable expectation that employees are or may be exposed to heat at or above the initial heat trigger” 

• • develop and implement a monitoring plan covering each such work area 

• • re-evaluate an area each time there is a change in production, processes, equipment, controls, or a substantial increase in outdoor temperature that may affect indoor work 

These efforts must involve affected employees, and be document in the HIIPP. 

Requirements at or above the initial heat trigger

When employees are exposed to heat at or above the initial heat trigger, the employer must do the following: 

• provide potable drinking water (“fresh, pure, and suitably cool”) to employees 

• located “readily accessible” to employees 

• suitably cool 

• in sufficient quantity to allow each employee 1 quart per hour 

• provide break areas –  

• • outdoors - either shaded or air conditioned, that can accommodate all employees on break 

• • indoors – air conditioned, or with increased air movement 

• acclimatization -  

• • new employees – during first week, scale up daily proportion of shift in hot conditions 20-40-60-80-100 percent 

• • returning employees (after more than 14 days away from hot conditions) - during first week, scale up daily proportion of shift in hot conditions 50-60-80-100 percent 

• allow and encourage individual (paid) rest breaks as needed 

• if personal protective equipment (PPE) is provided, ensure that cooling properties are maintained 

• maintain effective 2-way communication with employees, and use it regularly 

Requirements at or above the high heat trigger

When employees are exposed to heat at or above the high heat trigger, the employer meet the requirements for the initial heat trigger, and also do the following: 

• provide (paid) rest breaks, at least 15 minutes per 2 hours (not counting time to walk to rest area or don/doff PPE), in locations meeting standards above; meal breaks can count 

• observe for signs and symptoms, using co-worker buddy system, supervisor/coordinator observation, or effective 2-way communication 

• when high heat trigger is met or anticipated to be met, inform employees of importance of drinking plenty of water, right to rest, how to seek help if needed, and (for mobile employees) location(s) of water and rest area(a) 

Heat emergency response and planning

HIIPPs must include a Heat Emergency Response Plan, including the following: 

• list of emergency phone numbers (e.g., 911) 

• description how employees can contact supervisor or emergency medical services 

• individual(s) assigned to ensure invocation of heat emergency procedures 

• how to transport employee to pickup location for emergency medical providers 

• clear and precise directions to worksite, to provide to emergency medical dispatchers 

• procedures for response to employee experiencing signs and symptoms of heat-related illness (proposed standard specifies elements) 

Training

Employers must provide training to employees, including  

• heat stress hazards 

• heat-related injuries and illnesses 

• risk factors for heat-related injury or illness 

• signs and symptoms of heat-related illness and which ones require immediate emergency action 

• importance of removing PPE that may impair cooling during rest breaks 

• importance of taking rest breaks to prevent heat-related illness or injury, and that rest breaks are paid 

• importance of drinking water to prevent heat-related illness or injury 

• locations of break areas and employer-provided water 

• importance of employees reporting any signs and symptoms of heat-related illness (their own and in co-workers) 

• all policies and procedures applicable to the employee’s duties, as indicated in the HIIPP 

• identity of the heat safety coordinator(s) 

• requirements of this standard 

• how the employee can access the work site’s HIIPP 

• employee right to the protections required by this standard  

• any special procedures for working in excessively high heat areas 

Employers must also provide training to supervisors covering this information and their responsibilities. 

Annual refresher training is required, and supplemental training when information or conditions change. 

• cool-down areas (“an indoor or outdoor area that is blocked from direct sunlight and shielded from other high radiant heat sources to the extent feasible and is either open to the air or provided with ventilation or cooling”, readily accessible, and not subject to other unsafe or unhealthy conditions) where employees can sit without being in physical contact with each other 

• as close as practicable to the work area 

• large enough to accommodate employees who remain onsite during their meal period 

• maintained at no more than 82oF unless the employer demonstrates this is infeasible 

• allow and encourage employees to take preventative breaks in a cool-down area when the employee feels the need to do so, monitor each such employee’s well-being, and provide appropriate first aid or emergency response to heat illness 

Additional provisions

In addition to the HIPP and implementation procedures, the proposed standard requires: 

- record keeping, including retention of monitoring records for at least 6 months 

- requirement that water and services for employees be provided at no cost, including full pay while undertaking training and breaks 

What happens now? 

Comments on this proposal are due December 30, 2024. Whether and how fast OSHA proceeds will probably depend on who wins this year’s US Presidential election – President Harris’ OSHA would probably finalize and enforce the rule, while President Trump’s OSHA would probably delay or withdraw it. 

Readers should note that a number of states already have standards covering outdoor work, and that on July 23, 2024, California adopted new requirements governing indoor workplaces (8 California Code of Regulations (CCR) 3396), which expand on longstanding rules for outdoor workplaces (I wrote about California’s new rule HERE). 

Self-Assessment Checklist 

Do any of my organization's workers work in outdoor locations where ambient heat may create a hazard of heat illness? 

Do any of my organization's workers work in indoor locations where ambient heat may create a hazard of heat illness (e.g., enclosed spaces, work in manufacturing or other processes involving hot materials or equipment, and/or in confining and heat-retaining clothing and equipment)? 

If so, does the organization provide appropriate: 

• Training (tailored to the workplace source(s) of heat hazards, preventive measures, and responses to heat illness? 

• Water? 

• Shade or other appropriate ways for workers to cool down? 

• Planning and procedures? 

Does the organization include assessment of heat hazards in the design and construction of new facilities, and in structuring of work activities? 

Where Can I Go For More Information? 

• OSHA

- proposed rule (8/30/24 Federal Register) 

- “Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings Rulemaking” webpage

- “Heat” webpage 

• National Weather Service Heat Index
• NIOSH, “Criteria for a Recommended Standard - Occupational Exposure to Heat and Hot Environments” (DHHS (NIOSH) Publication No. 2016-106) (presents NIOSH Recommended Alert Limits in Figure 8-1) 

About the Author

Jon Elliott is President of Touchstone Environmental and has been a major contributor to STP’s product range for over 30 years. 

Mr. Elliott has a diverse educational background. In addition to his Juris Doctor (University of California, Boalt Hall School of Law, 1981), he holds a Master of Public Policy (Goldman School of Public Policy [GSPP], UC Berkeley, 1980), and a Bachelor of Science in Mechanical Engineering (Princeton University, 1977).

Mr. Elliott is active in professional and community organizations. In addition, he is a past chairman of the Board of Directors of the GSPP Alumni Association, and past member of the Executive Committee of the State Bar of California's Environmental Law Section (including past chair of its Legislative Committee).

You may contact Mr. Elliott directly at: tei@ix.netcom.com