Page 26 - Occupational Health & Safety, May 2017

INDUSTRIAL HYGIENE
A Framework for Hazard Banding
Exposure limits are absent for thousands of chemicals, creating a need for guidance that occupational exposure banding can help to fill, according to the authors of a new guidance document.
icity data to assign a range of concentrations to which chemical exposures should be controlled, with the resulting ranges defining the exposures that are ex- pected to protect workers’ health, it states.
Three-Tiered Assessment Process
The guidance document explains that, as it is cur- rently practiced, hazard banding requires significant technical expertise in industrial hygiene. And so, to address that limitation, the NIOSH process provides a three-tiered assessment process that allows the tech- nique to be applied with traditional occupational hy- giene expertise, as well as the option of more in-depth processes done in consultation with specialists in oc- cupational medicine and toxicology. The three tiers in the process are described this way:
Tier 1: “Qualitative OEB assignment based on GHS. Tier 1 involves assigning the OEB 10 based on criteria aligned with specific GHS hazard codes and categories. It is intended for individuals with basic toxicology knowledge. Chemicals with potential for irreversible health effects at relatively low doses war- rant assigning band D or band E. Chemicals that are likely to cause reversible health effects are categorized in band C. Bands A and B are not assigned in Tier 1. Since there are relatively low data requirements for Tier 1, there is not enough information to suggest ex- posure ranges for chemicals Bands A and B in Tier 1. In general, Tier 1 can be used as a quick screening method, but NIOSH recommends going to Tier 2 if the user expertise and data are available.”
Tier 2: “Semi-quantitative OEB assignment based on secondary sources: Tier 2 involves assigning the OEB on the basis of key findings from prescribed lit- erature sources, including use of data from specific types of studies. It is intended for individuals with intermediate toxicology knowledge. Tier 2 is more quantitative in nature than Tier 1. Individuals per- forming Tier 2 assessments will need to determine a point of departure by using the instructions that are provided for endpoints to support assigning chemi- cals into bands A, B, C, D, or E.”
Tier 3: “Expert Judgement: OEB based on primary sources and expert judgement: Tier 3 involves the use of expert judgement to assign the OEB based on in- depth review of health effects studies. It should only be performed by individuals with advanced toxicol- ogy knowledge. Tier 3 involves a more quantitative comprehensive evaluation of the scientific informa-
Defining Occupational Exposure Banding
Occupational exposure banding: (also called hazard banding) a systematic process using quali- tative or quantitative hazard information on se- lected health effect endpoints to identify potential inhalation-based exposure ranges or categories for guiding occupational risk assessment and risk management. (NIOSH External Review Draft)
BY JERRY LAWS
NIOSH scheduled a public meeting in Cin- cinnati this month to discuss and hear from industrial hygiene stakeholders about a March 2017 draft Current Intelligence Bul-
letin titled “The Occupational Exposure Banding Pro- cess: Guidance for the Evaluation of Chemical Haz- ards.” Weighing in at 141 pages, it explains the process as one seeking “to create a consistent and documented process to characterize chemical hazards so timely and well-informed risk management decisions can be made for chemicals lacking OELs [occupational ex- posure limits].”
The meeting is scheduled to begin at 9 a.m. on May 23 at NIOSH’s Robert A. Taft Laboratories and will be available via a live webcast. Comments about the guidance document may be submitted until June 13 via www.regulations.gov. (search for CDC-2017- 0028 and Docket No. NIOSH-290).
The executive summary portion of the document explains that, according to EPA, the Toxic Substances Control Act Chemical Substance Inventory contains more than 85,000 chemicals that are commercially available, yet only about 1,000 of them have been as- signed an authoritative (government, consensus, or peer reviewed) OEL.
This graphic illustrates the number of chemicals in com- merce vs. chemicals with occupational exposure limits. (NIOSH External Review Draft, page 18)
“Furthermore, the rate at which new chemicals are being introduced into commerce significantly out- paces OEL development, creating a need for guidance on thousands of chemicals that lack reliable exposure limits,” it says.
Guidance for thousands of chemicals that lack OELs is needed, and the occupational exposure band- ing process is useful because it employs chemical tox-
22 Occupational Health & Safety | MAY 2017
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