OSHA Proposes Nationwide Workplace Heat Safety Standard

OSHA has proposed a nationwide workplace heat safety standard to reduce heat-related injuries and illnesses by requiring employers to implement comprehensive heat safety measures for indoor and outdoor workers.

• By Susan F. Wiltsie, Elizabeth England
• Sep 13, 2024

On July 2, 2024, OSHA released its long-awaited proposed rule to prevent heat-related injuries and illnesses in the workplace. OSHA initiated the rulemaking process in October 2021 as part of its ongoing heat-related illness prevention initiative.

The proposed rule applies to most employers under OSHA’s jurisdiction and covers work in both indoor and outdoor settings, with exclusions for short-term exposure (15 minutes or less per hour), indoor sedentary work activities, indoor sites (including vehicles) kept below 80 degrees Fahrenheit, remote work and emergency response activities. The rule borrows from standards set by state occupational safety and health agencies, such as Cal/OSHA, which already impose heat safety measures on employers in their states.

The proposed rule requires employers to develop a Heat Injury and Illness Prevention Plan (HIIPP) to evaluate and control heat hazards in the workplace. As part of the HIIPP, employers will have to designate a heat safety coordinator and develop a heat emergency response plan with the involvement of non-managerial employees and their representatives.

Employers also would be required to monitor heat conditions at indoor and outdoor work areas. For indoor work sites, this includes implementing a monitoring plan covering work areas where employees are likely to be exposed to a heat index of 80 degrees Fahrenheit and above. Records of indoor monitoring data must be maintained for at least 6 months.

For outdoor work areas, employers can monitor heat conditions by tracking local heat index forecasts provided by the National Weather Service or other reputable sources or measuring the heat index as closely as possible to the work area and with “sufficient frequency” to determine with reasonable accuracy employees’ exposure to heat.

Employers must seek the input of non-managerial employees and their representatives when evaluating the work site to identify indoor exposure areas and when developing and updating outdoor monitoring plans. 

The proposed rule requires employers to implement specific measures to mitigate heat-related risks to employees when the temperature reaches an Initial Heat Trigger (a heat index of 80 degrees Fahrenheit), including the following:

• Readily accessible cool drinking water (at least one quart of water per employee per hour)
• Break areas at outdoor work sites with cooling measures, such as an air-conditioned enclosed space, artificial shade (e.g., tent or pavilion) or natural shade (e.g., trees), but shade from equipment is not sufficient
• Break areas at indoor work sites with air conditioning or increased air movement
• Controls for indoor working areas (such as air conditioning or fans)
• Paid rest breaks if needed to prevent overheating
• Regular and effective two-way communication.

The proposed rule also will require employers to implement acclimatization protocols upon the Initial Heat Trigger for new workers and workers returning after an absence of 14 days or more. Employers can choose between applying the High Heat Trigger measures (discussed below) for the employee’s first week on the job, even if the heat index does not exceed 90 degrees Fahrenheit or gradual acclimatization, according to a schedule recommended by the National Institute for Occupational Safety and Health (NIOSH).

Additional safety measures required when the High Heat Trigger is met (a heat index of 90 degrees Fahrenheit) include: 

• Mandatory, paid 15-minute rest breaks at least every two hours in break areas with cooling measures
• Observation of employees for signs and symptoms of heat-related illness, such as a mandatory “buddy system” or observation by a supervisor or heat safety coordinator
• A hazard alert to remind employees of the importance of drinking water, taking rest breaks and how to seek help
• Warning signs at indoor work areas with ambient temperatures that regularly exceed 120 degrees.

Employers will need to train all employees on heat safety prior to any work at or above the initial heat trigger. The proposed rule also requires annual refresher training and supplemental training after certain heat-related injuries or illnesses at the work site. 

The proposed rule is available at www.osha.gov/heat-exposure/rulemaking, but it has not yet been officially published in the Federal Register. Its publication will trigger a 120-day public comment period, after which OSHA will consider the comments and hold an informal public hearing before publishing a final rule.

The rule’s future likely will hinge upon who wins the presidential race, as a Republican administration may be likely to abandon the rulemaking process (if it is not final).

If the rule takes effect, it will face increased scrutiny in light of the US Supreme Court’s decision in Loper Bright v. Raimondo. Loper Bright overturned the longstanding Chevron deference doctrine, which permitted an agency’s interpretation of ambiguous statutory language to stand as long as it was deemed a reasonable interpretation of the implementing statute.

OSHA relies on its interpretation of the OSH Act to justify its workplace standards, including the proposed heat standard. In the OSH Act, Congress authorized OSHA to promulgate workplace health and safety standards “whenever the Secretary [of Labor]…determined that a rule should be promulgated in order to serve the objectives of this Act.” 29 U.S.C. § 655(b). 

Courts historically have deferred to OSHA’s authority, including on the basis of Chevron deference. Loper Bright will allow employers to challenge new OSHA standards as exceeding OSHA’s authority under the OSH Act. For example, an employer could argue that a particular OSHA standard does not advance the health and safety of workers and therefore exceeds OSHA’s statutory authority. While courts would have previously deferred to OSHA’s reasonable statutory interpretations, such deference no longer applies. In a 2020 case, the DC Circuit specifically held that Chevron entitled the Secretary of Labor to deference with respect to the applicability of a safety-standard regarding eyewash stations to construction industry employers, even though, as originally passed, the regulations only applied to federal contractors. Kiewit Power Constructors Co. v. Sec'y of Lab., U.S. Dep't of Lab., 959 F.3d 381, 385 (D.C. Cir. 2020). Such deference would no longer protect OSHA after Loper Bright.

Many observers expect challenges to the proposed rule. Assuming these challenges materialize, courts will apply their own judgment when assessing whether the proposed standard comports with the legislative delegations of authority in the OSH Act.