Chemicals, EHS Management

NIOSH Issues Guidance for Hazardous Substances with No Clear OEL

The National Institute for Occupational Safety and Health (NIOSH) released new guidance for determining the level of hazards for substances with no occupational exposure limit (OEL) established by a government agency, by a standard-setting body, or in peer-reviewed literature.

Group of men working at a chemical warehouse classifying barrels

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A large number of chemicals have no clearly defined OEL. The NIOSH Occupational Exposure Banding Process for Chemical Risk Management offers employers a strategy for assigning chemicals to a category or “band” to decide how to best protect workers from harmful exposures.

Characteristics of NIOSH’s process include:

  • A three-tiered system allowing users of varying expertise to use the process;
  • A method for determining health impacts by considering nine separate health outcome criteria that include acute toxicity, carcinogenicity, and skin sensitization;
  • Hazard-based categories linked to ranges of exposure; and
  • A process that was evaluated by determining exposure bands for chemicals with existing OELs.

Over 85,000 Chemicals, 1,000 OELs

NIOSH is offering the occupational exposure banding process to address a problem employers face in choosing which chemicals to allow in their workplaces. For the over 85,000 commercially available chemicals in the Toxic Substances Control Act (TSCA) Chemical Substance Inventory, only about 1,000 have a government, consensus, or peer-reviewed OEL.

“In the absence of formalized OELs, the exposure banding approach serves to identify workplace hazards and helps employers implement control strategies that keep workers safe on the job,” Director John Howard, MD, said in a NIOSH statement.

NIOSH also has provided an occupational exposure banding e-Tool on its website.

Health End Points

NIOSH’s process considers data about nine separate health hazards to determine the appropriate exposure band. The nine health end points weighed by the process are:

  • Acute toxicity;
  • Carcinogenicity;
  • Eye damage/irritation;
  • Genotoxicity;
  • Reproductive toxicity;
  • Respiratory sensitization;
  • Skin sensitization;
  • Skin corrosion and irritation; and
  • Specific target organ toxicity.

The occupational exposure banding process assigns a chemical to one of five control bands from A to E. Chemicals in the A band have the lowest potential for adverse health effects. Those in the E band have the highest health hazard potential.

Three-Tiered Process

Tier 1 of NIOSH’s three-tiered process is the easiest to use and requires relatively little information or specialized training. Tier 1 is appropriate for evaluating a large number of chemicals and deciding which ones to prioritize for elimination or substitution.

A workplace safety and health generalist can perform a Tier 1 assessment using information provided on a safety data sheet conforming to Globally Harmonized System criteria.

Each successive tier requires more specific information about the chemicals evaluated and more sophisticated user training. Tier 2 requires either an occupational hygienist or safety managers trained in chemical risk management. Tier 3 requires the type of expert judgment only a toxicologist or experienced occupational hygienist would possess, as well as all available data on the chemical being assessed. Some information needed can only be found by performing a thorough review of scientific literature.

Use of the occupational exposure banding process is not required by regulation. It also is not a substitute for complying with OSHA’s permissible exposure limits. The process is a tool for evaluating the hazards of chemicals without any established limit.

Once a chemical has been evaluated and assigned a band, the occupational hygienist or safety manager then must decide which controls in the hierarchy of controls are appropriate to limit employee exposure.