Since the development of occupational exposure limits (OELs) for chemicals used in the workplace is so time-consuming and resource intensive, the National Institute for Occupational Safety and Health (NIOSH) has developed a new and faster way for initially categorizing chemical hazard exposures—band it! We’ll take a look at a draft document recently released by NIOSH for a quicker way to assess workplace chemical hazards and how environment, health, and safety (EHS) managers can use it.
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The Problem
There are over 85,000 chemicals on the U.S. Environmental Protection Agency’s (EPA) Toxic Substances Control Act (TSCA) Chemical Substance Inventory. The Occupational Safety and Health Administration (OSHA) estimates that over 40 million employees are potentially exposed to hazardous chemicals in over 5 million workplaces. According to NIOSH, only about 1,000 chemicals have been assigned an occupational exposure limit (OEL). Exposures to chemicals at concentrations above their OEL are considered unsafe.
Although NIOSH and other agencies are in the process of developing new OELs and updating existing OELs, NIOSH sees the need for guidance for the thousands of chemicals that currently lack reliable OELs.
A Partial Solution—Band It
Occupational exposure banding is a process of quickly assigning chemicals into specific categories or bands. These bands are assigned based on a chemical’s potency and the negative health outcomes associated with exposure to the chemical. The output of this process is an occupational exposure band (OEB), which corresponds to a range of exposure concentrations that is expected to be protective to worker health. NIOSH recently released a draft document outlining a process to apply occupational exposure banding to a broad spectrum of occupational settings to determine a potential range of chemical exposure levels that can be used as targets for exposure controls to reduce risk among workers.
Five Bands
According to NIOSH, the OEB process guides a user through the evaluation and selection of health hazard information. Using the guide, users will be able to identify the appropriate OEB from among five categories of severity of health outcomes (bands A to E, where band A is least severe and band E is most severe).
A key feature of NIOSH’s banding process is the use of the OEB as a tool for considering the overall hazard profile for multiple health hazard endpoints at the same time. The band-specific technical criteria apply to nine potential human health outcomes:
- Carcinogenicity,
- Reproductive toxicity,
- Specific target organ toxicity,
- Genotoxicity,
- Respiratory sensitization,
- Skin sensitization,
- Acute toxicity,
- Skin corrosion and irritation, and
- Eye damage/irritation.
The overall band is assigned on the basis of protection against the most severe effects.
Three Tiers
Since hazard banding usually requires significant expertise in industrial hygiene, NIOSH has developed a three-tiered process intended to open up assessment process for wider usage.
Tier 1 involves assigning the OEB based on criteria aligned with specific Globally Harmonized System of Classification and Labelling of Chemicals (GHS) hazard codes and categories. It is intended for individuals with basic toxicology knowledge.
Tier 2 involves assigning the OEB on the basis of key findings from prescribed literature sources, including use of data from specific types of studies. It is intended for individuals with intermediate toxicology knowledge.
Tier 3 involves the use of expert judgement to assign the OEB based on in-depth review of health effects studies. According to NIOSH, it should only be performed by individuals with advanced toxicology knowledge.
Tune in to tomorrow’s Advisor for how EHS managers could potentially use NIOSH’s proposed Tier 1 OEB process for workplace chemical evaluations.