A recommended exposure limit (REL) is an

occupational exposure limit An occupational exposure limit is an upper limit on the acceptable concentration of a hazardous substance in workplace air for a particular material or class of materials. It is typically set by competent national authorities and enforced by legi ...

that has been recommended by the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

National Institute for Occupational Safety and Health The National Institute for Occupational Safety and Health (NIOSH, ) is the List of United States federal agencies, United States federal agency responsible for conducting research and making recommendations for the prevention of work-related occ ...

. The REL is a level that NIOSH believes would be protective of worker safety and health over a working lifetime if used in combination with engineering and work practice controls, exposure and medical monitoring, posting and labeling of hazards, worker training and

personal protective equipment Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, elect ...

. To formulate these recommendations, NIOSH evaluates all known and available medical, biological, engineering, chemical, trade, and other information. Although not legally enforceable limits, RELS are transmitted to the

Occupational Safety and Health Administration The Occupational Safety and Health Administration (OSHA; ) is a regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. The United States Congress established ...

(OSHA) or the

Mine Safety and Health Administration The Mine Safety and Health Administration (MSHA) () is a small agency of the United States Department of Labor which administers the provisions of the Federal Mine Safety and Health Act of 1977 (Mine Act) to enforce compliance with mandatory sa ...

(MSHA) of the

U.S. Department of Labor The United States Department of Labor (DOL) is one of the executive departments of the U.S. federal government. It is responsible for the administration of federal laws governing occupational safety and health, wage and hour standards, unem ...

for use in promulgating legal standards. All RELs are located in the ''NIOSH Pocket Guide to Chemical Hazards'', along with other key data for 677 chemical or substance groupings. The ''Pocket Guide'' is a source of general industrial hygiene information for workers, employers, and occupational health professionals. NIOSH recommendations are also published in a variety of documents, including: * Criteria documents – These recommend workplace exposure limits and appropriate preventive measures to reduce or eliminate adverse health effects and accidental injuries. * Current Intelligence Bulletins (CIBs) – These share new scientific information about occupational hazards, highlighting a formerly unrecognized hazard, reporting new data on a known hazard, or presenting information on hazard control. * Alerts, Special Hazard Reviews, Occupational Hazard Assessments, and Technical Guidelines - These assess the safety and health problems associated with a given agent or hazard and recommend appropriate control and surveillance methods. Although these documents are not intended to supplant the more comprehensive criteria documents, they are prepared to assist OSHA and MSHA in the formulation of regulation. In addition to these publications, NIOSH periodically presents testimony before various Congressional committees and at OSHA and MSHA rulemaking hearings.

Understanding and applying NIOSH recommended exposure limits

(NIOSH) RELs are designed to protect the health and well-being of workers by recommending safe exposure levels. To really use these guidelines well, safety professionals need to understand the recommended exposure levels, how to measure them, and ways to make sure workers aren't exposed to harmful stuff. It's not just about knowing the numbers; it's also about checking regularly and making changes if needed to keep everyone safe. RELs are written as time-weighted average (TWA) exposures. This TWA is calculated for a standard workday of up to 10 hours, over a 40-hour workweek. This is slightly different to

permissible exposure limit The permissible exposure limit (PEL or OSHA PEL) is a legal limit in the United States for exposure of an employee to a chemical substance or physical agents such as high level noise. Permissible exposure limits were established by the Occupational ...

(PELs), which are calculated for 8 hours over a 40-hour workweek instead. NIOSH recognizes that certain scenarios demand more immediate attention and has therefore introduced additional measures. Sometimes it's not always about the whole day and a worker might be around a lot of the stuff in a short burst. So, they set a short-term exposure limit (STEL), meaning the concentration of a substance that should never be exceeded within a specified 15-minute period. There is also a ceiling limit (C). This is a substance no one should be exposed to, even for a moment. These guidelines aim to strike a balance; it is to keep workers safe from harm without going overboard and making things inefficient in the workplace. The RELs, unlike permissible exposure limits or PELs set by

OSHA The Occupational Safety and Health Administration (OSHA; ) is a regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. The United States Congress established ...

, are merely guidelines -- they are not legally enforceable. An employer cannot be held liable, but they can try to implement these in the workplace. These guidelines are crucial for workplace safety. RELs undergo more frequent revisions and tend to be more stringent compared to PELs established by OSHA. The strictness inherent in RELs align with the latest scientific understanding and advancements in occupational health. This prioritizes knowledge in worker safety.

References

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External links

NIOSH Pocket Guide to Chemical Hazards
National Institute for Occupational Safety and Health Environmental standards Chemical safety Occupational safety and health