As heat records continue to be broken around the country, mine operators are having to direct more time and attention to protecting their personnel from the dangers of heat stress.

Quick Hits

  • MSHA issued a July 2023 heat alert encouraging mine operators to provide heat-stress recognition training, monitoring, and personal protective equipment.
  • OSHA is also taking steps to address heat illness and injury prevention.
  • MSHA, which does not have regulations related to heat stress, may engage in rulemaking in the future, given OSHA's attention to heat hazards.

This is no longer just a summer concern. In many parts of the country, especially in the Southwest, the usual respite offered by the end of the summer and the cooler months of September and October are not necessarily materializing. In Texas, for instance, the number of 100-degree days in September 2023 was at an all-time high.

With this new reality, mine operators are implementing heat protection programs to enable managers and employees to identify and alleviate the dangers of heat stress. In most cases, these efforts by mine operators are voluntary and not related to any specific regulatory requirement. These programs generally include administrative controls to rotate miners on hot jobs, provision of proper protective clothing and shade, and direction regarding frequent hydration.

Many mine operators also conduct training regarding how to identify the signs of heat stress, with emphasis on symptoms like cramping, high body temperature, red or spotted skin, and general confusion.

These efforts by mine operators are consistent with recommendations set out in a July 2023 heat alert issued by the Mine Safety and Health Administration (MSHA). In that alert, the agency encouraged operators to provide heat-stress recognition training, monitoring, and personal protective equipment. While MSHA has no regulations related to heat stress, it will be a likely target of rulemaking in the future, given the attention currently focused on this hazard by the Occupational Safety and Health Administration (OSHA) and a number of states.

OSHA issued an advance notice of proposed rulemaking for heat injury and illness prevention in October 2021. That process has not moved along very far, but those with OSHA-regulated operations like asphalt plants and highway construction are aware that OSHA has been utilizing its General Duty Clause to address workplace heat hazards. The General Duty Clause requires employers to furnish a work environment "free from recognized hazards that are causing or are likely to cause death or serious physical harm."

In conjunction with this enforcement, OSHA issued a July 2023 heat hazard alert which specifically put employers on notice that they are responsible for protecting workers from heat illness. The alert identified minimum steps employers should take to meet this responsibility.

These include adequate cool water, rest breaks, shade, opportunities for workers to gradually acclimatize to the heat, and training for heat illness emergencies.

Several states—California, Minnesota, Nevada, and Washington—have proposed or implemented heat illness prevention standards, and more states are sure to follow.

OSHA Assistant Secretary Doug Parker was previously the chief of the California Division of Occupational Safety and Health (Cal/OSHA), and that state's standard is likely to be the template for the federal one. The key component of that template for employers is the development of a written heat illness prevention plan, which delineates the requirements dictated by the standard—including requirements for training and heat illness emergency response.

The general requirements of the California standard are triggered by specific temperature thresholds. At 80 degrees, employers must provide close access to shade and drinking water. Such use of water and shade is also required to be monitored and encouraged by supervisory personnel. Supervisors must also be trained to monitor weather conditions (specifically heat and humidity) to identify heat waves that may necessitate acclimatization of personnel to deal with temperature increases over a period of days.

At 95 degrees, specific high heat procedures are activated. These include effective voice communication or direct observation of all employees. Frequent communication with employees working by themselves or in smaller groups, along with a mandatory buddy system, must also be implemented.

Management is also required to hold a pre-shift meeting during such conditions to remind employees of these high-heat procedures and their right to a cool-down rest period when necessary.

Given the temperature trends of the last few years, most mine operators are well ahead of the curve in voluntarily implementing safe work procedures for protecting their employees from heat illness. Nonetheless, federal requirements are probably not too far off on the horizon, so operators may want to examine their procedures to get ready.

A version of this article was previously published in Pit & Quarry magazine.

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