Maryland’s New Heat Illness Prevention Standard
- Nicole Cook
- Apr 29
- 3 min read
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The Maryland Occupational Safety and Health (MOSH) Division of Labor and Industry published its new Heat Illness Prevention Standard as a final regulation on September 20, 2024. This new workplace safety regulation went into effect just 10 days later, on September 30, 2024. The new standard—found in COMAR 09.12.32—applies to all workplaces where the heat index reaches 80 degrees Fahrenheit or higher, regardless of whether the work is indoors or outdoors. This includes farms. Keep reading for an overview of the new requirements and what steps employers need to take to ensure compliance.
Who Must Comply?
The regulation covers most Maryland employers, including those in agriculture. The rule does not apply to emergency operations (e.g., first responders or utility providers), incidental heat exposures of less than 15 consecutive minutes per hour, or situations where mechanical ventilation or fans keep the heat index below 80 degrees Fahrenheit.
What Must Employers Do?
Employers whose workers are regularly exposed to heat must now monitor the heat index throughout the work shift using approved methods. In buildings or structures without mechanical ventilation, employers must measure both temperature and humidity at the actual worksite to calculate the heat index accurately.
If workers are exposed to heat index levels of 80°F or above, employers must implement an already-prepared, written, compliant Heat Illness Prevention and Management Plan. The written plan must be made available and accessible to employees and to MOSH upon request. The plan must be specific to your work place (meaning it cannot be a generic plan), and it must include, among other things:
Providing easy access to sufficient cool, potable drinking water—at least 32 ounces per employee, per hour per work day;
Clear methods for encouraging and allowing employees to hydrate regularly;
Training to help workers and supervisors monitor for and recognize symptoms of heat-related illnesses such as heat exhaustion and heat stroke;
Plans for providing compliant shaded or cool, climate-controlled rest breaks as needed to prevent illness;
A compliant, structured heat acclimatization process for new or returning workers over a period of up to 14 days; and
Ongoing education and annual re-training for all employees, including training on the risks of heat illness and the specifics of the heat illness prevention plan, and additional training for supervisors on how to respond to heat illness symptoms.
Additional Protections at Higher Temperatures
Once the heat index reaches 90°F, additional safety measures must be taken. This includes more frequent monitoring, especially if temperatures are expected to rise significantly or when workers are in high radiant heat areas or wearing heat-restrictive clothing. In addition,
Workers must receive a minimum 10-minute cooled rest break every 2 hours; and
If the heat index climbs above 100°F, that rest time increases to 15 minutes every hour.
Also, employers must implement a hierarchy of control measures to reduce the risk of heat illness, including:
Engineering Controls: Use air conditioning, fans, ventilation, and other methods to reduce temperature and heat index.
Administrative Controls: Adjust work schedules, rotate employees, and reduce work intensity during peak heat periods.
Personal Protective Equipment: Use cooling garments or other personal protective equipment as a last resort if other controls are insufficient.
Importantly, all procedures and training must be provided in a format and language that employees can understand.
Emergency Preparedness and Re-Training
Employers are also required to develop emergency response procedures as part of their heat illness prevention plans. These procedures are intended to ensure prompt and effective action if a worker shows signs of heat illness.
In cases where a suspected or confirmed heat illness occurs on the job, the regulation mandates retraining for all relevant employees and supervisors. At a minimum, refresher training must be conducted once per year.
Resources and Staying Informed
If you haven’t already, you should review the new requirements, evaluate your methods for monitoring heat in both indoor and outdoor work settings, develop your heat illness prevention plan, and provide training to your employees to ensure compliance.
To support employers and workers in meeting these new requirements, MOSH issued information and guidance, which includes heat standards and education from other OSHA state plans, such as California, Oregon, and Washington.
MOSH is developing additional resources and guidance documents. Anyone interested in receiving updates can subscribe through the MOSH homepage by submitting their email on the MOSH Subscription Form.