December 21, 2023 / By Taylor Tarpey, Heather Lynch, and Andy Maier

Linking Risk Characterization and Risk Management: How to Optimize Tools for a Safer Workplace

AIHA and the Foundation for Chemistry Research and Initiatives (FCRI) hosted a series of workshops on occupational risk assessment. The fifth and final webinar in the Many Paths – One Goal series, which was held on Dec. 7, brought together a panel of experts to discuss approaches for characterizing and managing risks in the workplace. The experts presented an overview of risk characterization, the application of the hierarchy of controls, risk management in the context of regulations (for example, EPA’s implementation of the Toxic Substances Control Act), and emerging hazard control technologies and practices.

Occupational risk assessment, risk characterization, and risk management reflect a management process involving regular review and updates, with industrial hygienists regularly conducting assessments and monitoring workplaces for change. The process is complex—not a box-checking exercise—given that control strategies must consider the dynamics of the work environment (for example, temporal considerations including frequency and duration of tasks, and spatial considerations such as the density of workers). The exposure assessment phase of the occupational risk assessment process is particularly important as it informs risk characterization and ultimately supports the IH in controlling the identified hazards associated with the job.

Industrial hygienists rely on occupational exposure limits to assess health hazards for a given exposure scenario. While there are numerous OELs from a variety of sources, as one panelist pointed out, an occupational risk assessor must consider the basis for each OEL and apply a systematic approach to OEL selection for their situation. This is because OELs vary in the level of data available, the underlying risk policies of the organizations that establish them, and differences in application of risk methods. On the other hand, for many chemicals there are limited data and no published OELs, so other tools in the “hierarchy of OELs” need to be considered. To that end, exposure, hazard, and control banding—approaches that group workplace risks into categories, or bands, based on hazard and exposure information for the purpose of developing controls—may be used in situations with no published OELs. The panel noted many AIHA and other resources to guide the identification of OELs and related approaches to support risk characterizations.

Risk management programs involve applying controls and interventions to reduce, minimize, or eliminate hazardous conditions in the workplace. These programs rely on the hierarchy of controls, which outlines common control methods arranged from most preferred due to the likelihood for predictable and ongoing control of exposure (elimination/substitution) to least preferred (personal protective equipment). When considering engineering controls such as local exhaust ventilation, the IH must evaluate the emission source, the air pathway, and the worker behaviors that may influence exposure. Administrative controls and PPE are generally considered as supplemental approaches to further enhance engineering controls. Often, an IH must consider multiple controls to effectively reduce exposures.

Control plans can be complex because introduction or removal of one control method may increase the overall health and safety risk or introduce a new risk. For example, substituting a flammable solvent with a nonflammable alternative may remove the risk of flammability but introduce a chemical with a lower OEL based on more severe health effects. The IH must weigh the risks for a given control approach. Moreover, as noted during the panel discussion, workplaces are very dynamic, and the application of the hierarchy of controls must be process-focused and begin in the planning phases for new facilities or processes—that is, controls should be implemented during workplace design. The use of an exposure control and risk matrix may help the IH implement the appropriate control type or combination of controls. Thorough documentation of the selected control—such as in an exposure control plan—were noted in the panel discussion as helpful for ensuring the overall set of combined controls is optimized and tuned for the specific scenario.

For compliance purposes, the IH must consider the context of the regulation the actions are intended to address, particularly given the evolving scope of the amended Toxic Substances Control Act. EPA has the authority to regulate potentially unreasonable risks to workers from exposure to a given chemical through various means, including establishing an OEL known as an Existing Chemical Exposure Limit (ECEL). Several TSCA risk management rules released to date detail a specific Workplace Chemical Protection Program (WCPP) that EPA determined would reasonably be expected to control exposures to levels below the ECEL. Providing occupational information and data as early as possible can help tailor these risk management rules to specific occupational exposure scenarios.

Given the evolving regulatory landscape for risk management, locating key resources on risk management and exposure control strategies is central to developing an effective exposure control program. Agencies such as NIOSH work to generate new knowledge and exposure control technologies for the field of occupational health and safety. For example, NIOSH’s Prevention Through Design (PtD) initiative offers tools for employers to design new processes with hazard minimization in mind. NIOSH developed an exposure banding e-Tool using health hazard information to identify potential exposure ranges or categories. NIOSH also conducts research on equipment design, ventilation patterns, and PPE, and develops emerging technologies such as direct-reading instruments and sensor detection methods for exposure monitoring. These research efforts typically are summarized in guidance documents and case studies. Additionally, industry, trade, and organized labor groups, as well as many nonprofits and academic researchers, have developed resources for product stewardship programs and often have published risk management guidance available to workplaces.

A key challenge is ensuring this information reaches the target audiences. The panelists discussed risk communication strategies, emphasizing that effective communication leads to effective implementation of controls. For example, robust safety data sheets are an important tool for manufacturers to disseminate hazard information to downstream users, but—as many participant responders noted in a poll during the session—there is added value in supplementing SDS with additional information on product handling. Additionally, it is important to build trust with the workforce and ensure they are integral to the decision-making and control implementation process.

Overall, risk characterization and management require the careful consideration of many risks in the workplace. Managing exposures must be prioritized to ensure changes or improvements made to reduce exposure will keep overall risks—from all sources—minimized.

With the conclusion of the workshop series, a critical review will be published highlighting the key impacts of the series.

Image: Getty/AlexLMX

Other posts in this series:

AIHA’s First Workshop on Occupational Risk Assessment

Workshop Explores Uses of IH Exposure Data for Occupational Risk Assessment

Workshop Examines Opportunities for the Use of Exposure Modeling in Occupational Risk Assessment

Resources and Approaches for Dermal Exposure and Risk Assessment


The Synergist: "Many Paths, One Goal: Exploring Different Approaches to Occupational Risk Assessment" (February 2023).

By Taylor Tarpey, Heather Lynch, and Andy Maier

Taylor Tarpey, MPH, is a health scientist at Stantec.

Heather Lynch, MPH, DABT, is principal science advisor at Stantec.

Andy Maier, PhD, CIH, DABT, FAIHA, is the director of the nonprofit Occupational Alliance for Risk Science initiative and a principal health scientist at Stantec.


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