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Personal Author:
Lentz, Thomas J. ; Seaton, Melissa ; Rane, Pranav ; Gilbert, Stephen J. ; McKernan, Lauralynn T. ; ... More +
Lentz, Thomas J. ; Seaton, Melissa ; Rane, Pranav ; Gilbert, Stephen J. ; McKernan, Lauralynn T. ; Whittaker, Christine Less -
Corporate Authors:
National Institute for Occupational Safety and Health.
Description:
"Occupational exposure limits (OELs) play a critical role in protecting workers and emergency response personnel from exposure to dangerous concentrations of hazardous materials [Cook 1987; Deveau et al. 2015; Paustenbach 1998; Nikfar and Malekirad 2014; Schulte et al. 2010; Skowroñ and Czerczak 2015]. In the absence of an OEL, determining the appropriate controls needed to protect workers from chemical exposures can be challenging. According to the U.S. Environmental Protection Agency (US EPA), the Toxic Substances Control Act (TSCA) Chemical Substance Inventory currently contains over 85,000 chemicals that are commercially available [US EPA 2015], yet only about 1,000 of these have been assigned an authoritative (government, consensus, or peer reviewed) OEL. Furthermore, the rate at which new chemical substances are being introduced into commerce significantly outpaces OEL development, creating a need for guidance on thousands of chemical substances that lack reliable exposure limits [OSHA 2014]. To protect worker health in the absence of an OEL, occupational hygienists and safety professionals use a variety of tools such as safety data sheets, exposure monitoring, medical surveillance, and toxicity testing to make risk management decisions. However, one of the challenges faced by occupational hygienists and safety professionals is that despite the myriad sources of data on chemical substances, they have no decision-making framework to screen and discriminate the most relevant data when assessing chemical substances and developing exposure control guidance. Occupational exposure banding, also known as hazard banding or health hazard banding, is a systematic process that uses qualitative and quantitative hazard information on selected health-effect endpoints to identify potential exposure ranges or categories. The National Institute for Occupational Safety and Health (NIOSH) occupational exposure banding process seeks to create a consistent and documented process with a decision logic to characterize chemical hazards so that timely, well-informed risk management decisions can be made for chemical substances that lack OELs. Users can band a chemical manually or by using the occupational exposure banding e-Tool. Overall, this document provides the background, rationale, and instructions for the occupational exposure banding process and gives guidance for risk managers to identify control levels for chemicals without authoritative OELs. Using hazard-based categories to communicate potential health concerns serves to signal workers and employers of the need for risk management. This concept is not new. Numerous hazard classification and category-based systems have seen extensive use in the occupational setting. Such systems are deeply embedded in occupational hygiene practice, particularly in the pharmaceutical industry [NIOSH 2009c; Naumann et al. 1996], and are also elements of well-developed, modern hazard communication programs such as the United Nations 2013 Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The NIOSH occupational exposure banding process is distinguished from other hazard classification and category-based systems in several ways. The unique attributes of the NIOSH process include: (1) a three-tiered system that allows users of varying expertise to use the process; (2) determination of potential health impacts based on nine health endpoints separately; (3) hazard-based categories linked to quantitative exposure ranges; and (4) assessment of the process via extensive evaluation exercises to determine consistency of the occupational exposure banding process with OELs. Each tier of the process has different requirements for data sufficiency, which allows a variety of stakeholders to use the process in many different situations. The most appropriate tier for banding depends on the availability and quality of the data, how it will be used, and the training and expertise of the user. Whereas Tier 1 requires relatively little information and modest specialized training, each successive tier requires more chemical-specific data and more user expertise to successfully assign an occupational exposure band (OEB). A primary goal of Tier 1 is to give the user a quick summary of the most important health effects associated with exposure to the chemical substance of interest and to quickly identify toxic chemical substances that should be considered for substitution or elimination. Tier 1 would likely be most appropriate when banding a large number of chemical substances and deciding which ones to prioritize for elimination or substitution. In general, Tier 1 can be used as a quick screening method and should be completed first, prior to progressing to Tier 2. NIOSH recommends always progressing to Tier 2 if user expertise and data are available, even when Tier 1 banding has been completed. Tier 2 requires the user to examine a number of publicly available databases and extract relevant toxicological and weight-of-evidence data to be used in the NIOSH banding algorithm. Tier 3 employs a critical assessment to evaluate experimental data and discern toxicological outcomes. A general overview of the entire process is in the next section, Occupational Exposure Banding at a Glance. The NIOSH occupational exposure banding process considers the totality of the information across all of the nine standard toxicological health endpoints: (1) carcinogenicity; (2) reproductive toxicity; (3) specific target organ toxicity; (4) genotoxicity; (5) respiratory sensitization; (6) skin sensitization; (7) acute toxicity; (8) skin corrosion and irritation; and (9) eye damage/irritation. The process looks at each health endpoint separately for each chemical substance, and the endpoint bands allow the user to make judgements about which health effects are the primary concerns for workers who are exposed. This type of specificity allows users to customize their control strategies on the basis of potency of the chemical substance and the target organ/health effect. In addition, the banding process considers multiple routes of exposure (e.g., inhalation, dermal, eye, and oral) to determine the overall OEB. Another important component of the NIOSH occupational exposure banding process is the five exposure bands. Occupational exposure banding uses limited chemical toxicity data to group chemical substances into one of five bands, ranging from A through E. These bands, or OEBs, define the range of air concentrations expected to protect worker health. Band E represents the lowest exposure concentration range recommendation, whereas band A represents the highest exposure concentration range [McKernan et al. 2016]. Users should note that throughout this document, bands that represent lower exposure ranges are assigned to more potent/toxic chemical substances than bands that represent higher exposure ranges. One major benefit of occupational exposure banding is that the amount of time and data required to categorize a chemical substance into an OEB is far less than that required to develop an OEL. An OEB is not meant to replace an OEL; rather, it serves as a starting point to inform risk management decisions when an OEL is not available. An OEB can also assist with prioritizing chemical substances for which an OEL should be developed and can guide users, including enterprises of all sizes, in setting internal OEBs or ranges for controlling exposures to specific chemical substances. The NIOSH occupational exposure banding process is one approach or tool for assessing chemical hazards and prioritizing control efforts. Occupational hygienists have several tools in their toolbox to protect and improve occupational health in the workplace. Likewise, there are several components in a comprehensive occupational safety and health program. For example, exposure monitoring, medical surveillance, engineering controls, OELs, quantitative risk assessments, and personal protective equipment are all tools routinely used. Occupational exposure banding is an additional tool for professionals to consider. Although occupational exposure banding will not solve every problem or address every need, it will be a helpful addition to the occupational hygiene toolbox because it provides a blueprint for making risk management decisions. NIOSH has performed evaluation exercises to assess consistency of the occupational exposure banding process with OELs. To evaluate the Tier 1 process, NIOSH compared the OELs of 606 chemical substances to the derived Tier 1 band for those chemical substances. This evaluation found that the NIOSH Tier 1 banding process resulted in a band that included the OEL or was more stringent than the OEL for 91% of chemical substances. Five iterative phases of Tier 2 reliability testing were performed to assess Tier 2 as the process evolved. These assessments involved over 130 chemical substances with OELs. Results of these evaluations show that Tier 2 OEBs are highly likely to be at least as stringent as OELs. Tier 2 OEBs include the OEL or are more stringent than the OEL for 98% of chemical substances tested. Comparing OEBs with OELs is not an appropriate comparison, given several considerations. OEBs are completely health-based concentration ranges derived from the totality of the toxicity information available for a specific chemical substance. OELs, by contrast, are derived with additional considerations, including possible adjustments for analytical feasibility, engineering control achievability, and in some cases economic factors. Consequently, given these additional adjustments for OELs, the OEBs and OELs will not always align perfectly. Overall, however, the results of the evaluation exercises demonstrate that the occupational exposure banding process is accurate and reproducible and can be a useful tool for evaluating chemical substances that do not have OELs. Although the occupational exposure banding process was developed for all chemical substances that lack OELs, it should not be applied to some, such as pharmaceutical drugs and radioisotopes. This document details other situations that warrant special consideration, such as banding nanomaterials or mixtures of two or more chemical substances. A substantial number of chemical substances lack authoritative OELs, and risk management guidance is needed for these. Occupational exposure banding is one additional tool that can provide such guidance. An OEB provides a range of air concentrations that is expected to be protective of worker health. The process and adherence to the resultant OEB are voluntary and are not required or tied to any legal obligations. This document details the use and application of the occupational exposure banding process and provides a summary of efforts taken to evaluate its comparability to OELs and usability." - NIOSHTIC-2

NIOSHTC no. 20056369

Suggested citation: NIOSH [2019]. Technical report: The NIOSH occupational exposure banding process for chemical risk management. By Lentz TJ, Seaton M, Rane P, Gilbert SJ, McKernan LT, Whittaker C. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2019-132, https://doi.org/10.26616/NIOSHPUB2019132


Subjects:
[+]
Air Pollutants, Occupational Hazardous Substances Occupational Exposure Risk Assessment Risk Management
DOI:
10.26616/NIOSHPUB2019132
Document Type:
Report
Collection(s):
Stephen B. Thacker CDC Library collection
Main Document Checksum:
[+]
urn:sha256:b8ba059a84df4a452091adf6d4f44b776724503d7d04e1c6a5ddb42c2df4729c
Download URL:
https://stacks.cdc.gov/view/cdc/79841/cdc_79841_DS1.pdf
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