ANITA BROUGHTON, EIT, CIH, is a human health risk assessor at Haley & Aldrich, Inc. and a member of the AIHA Risk Assessment Committee and the Product Stewardship Society. She can be reached at abroughton@haleyaldrich.com. MARYANN SANDERS is a toxicologist and product steward at Haley & Aldrich, Inc. and a member of the Product Stewardship Society. Sanders can be reached at msanders@haleyaldrich.com. SCOTT BOSTON, CIH, is a regulatory health specialist at Haley & Aldrich, Inc. and a member of AIHA and the Product Stewardship Society. He can be reached at sboston@haleyaldrich.com.
Team Players Chemical Risk Assessment Yields New Roles for Industrial Hygienists
Let's face it: the days when industrial hygienists were tied to the shop floor are over. Factors contributing to this shift include greater demand for quantitative (as opposed to qualitative) risk estimates to support decisions regarding human health and the environment; increased awareness of chemical risk; and an evolving regulatory landscape. Today, industrial hygienists enjoy a growing number of career opportunities due to their knowledge of the toxicological properties of chemicals used in the workplace and their ability to assess potential exposures.

Concerns about potential chemical exposure extend beyond workers involved in the manufacturing process. The public, especially members of sensitive sub-populations such as children and the elderly, may also be at risk. The public relies on regulators and experts to confirm that products do not harm the health of current or future generations from exposures in homes, communities, and workplaces. These technical professionals—human health risk assessors and product stewards—employ skills similar to those of many industrial hygienists, who can play a significant role in developing health protection regulations and risk assessment guidance. Industrial hygienists can also help manufacturers evaluate chemical exposures throughout the product life cycle and exposures associated with facility decommissioning, property reuse, and redevelopment. PRODUCT STEWARDSHIP Some industrial hygienists find themselves involved in aspects of product stewardship, a discipline that includes evaluating products throughout their life cycles to address health and environmental risks and confirming that regulatory compliance obligations are met. This rapidly evolving area of expertise grew out of concerns about the effects of chemical exposure from products on human health and the environment. These concerns have stimulated the exponential growth of global chemical and product regulations; as consumers become more educated on the contents of products and the choices available, many companies are choosing to regulate their own products. (To support professionals who have a role in product stewardship and sustainability, AIHA created the Product Stewardship Society in 2013. More information is available on the society's website.)
Product stewards may be required to apply health risk assessment guidelines to quantify the multiple potential exposure pathways associated with product use. These assessments support business requirements and consumer demands, and identify the need for product reformulations and regulatory obligations such as warning labels and notifications. In the U.S., regulatory agencies applicable to product stewardship include EPA, the Food and Drug Administration (FDA), the Securities and Exchange Commission (SEC), and various state regulatory departments. 
Some states, including California, have established safer consumer product regulations. For example, Proposition 65 requires that businesses notify Californians of significant releases of chemicals into the environment and the presence of significant amounts of chemicals in products, homes, and workplaces. Further, the California Safer Consumer Products regulations require an alternative assessment when a candidate chemical—that is, a chemical that exhibits a “hazard trait and/or an environmental or toxicological endpoint”—is present in certain consumer products. Methylene chloride in paint thinners is one example.
MULTI-PATHWAY EXPOSURE Although clothes can be laundered and work surfaces cleaned, residual chemicals may contribute to elevated body burdens from workplace exposures. Industrial hygienists have the skills to help evaluate health concerns that arise from chemicals inside a facility and those tracked, dispersed, emitted, released, or discharged from the workplace. A new focus on workers’ combined exposures from both inside and outside the workplace has spurred development of exposure assessment approaches for evaluating the entire workplace environment based on job function and human behaviors. One example is NIOSH’s Total Worker Health approach, which advocates for a holistic understanding of factors affecting worker safety and health. 
Several sources of information are available for chemicals in the workplace that have little or no current publicly available toxicological data. These sources include EPA’s ChemView database; the Agency for Toxic Substances and Disease Registry (ATSDR); NIOSH’s Registry of Toxic Effects of Chemicals (RTECS); the European Chemicals Agency (ECHA) Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) dissemination portal; and World Health Organization (WHO) publications.
And when the information necessary to quantitatively estimate health risk for a given chemical is not available, industrial hygienists and others are using information from chemicals with similar structure. For example, NIOSH’s draft occupational exposure banding (OEB) methodology may facilitate the evaluation of health risk and identify chemicals for possible elimination or substitution (read more about the NIOSH decision logic for OEBs in the March 2016 Synergist). In addition, the Organization for Economic Cooperation and Development (OECD) has developed QSAR, a toxicological toolbox that contains methods for estimating chemical properties, including hazards and toxicity, based on their molecular structure. 
Estimates of multi-pathway exposures and associated health risks can be quantified using published risk assessment guidance, particularly guidance on risk assessment of hazardous waste sites. Industrial hygienists can use OEB and QSAR to quantify potential health risks to the public from the use of consumer products; health risks to workers from multi-pathway exposures; and health risks that may result from the reuse of equipment, material, or land from former industrial sites. Some of these references and guidance documents are available via the AIHA Risk Assessment Committee Web page. FACILITY DECOMMISSIONING AND RE-OCCUPANCY Decommissioning of industrial facilities typically includes activities for which industrial hygienists are responsible while the facility is active. These activities include the decontamination of work surfaces and other building materials such as concrete floors and the removal of asbestos or lead-based paint. Industrial hygienists’ direct knowledge of the chemicals used while a facility was active is valuable during decommissioning; they are able to assess residual chemicals within building materials or on equipment to be sold, reused, or repurposed. 
A facility’s future tenant is often unknown, and restrictions on future use may be imposed based on the results of a risk assessment. Cleanup criteria must consider potential future uses and combined pathways of potential exposure. For example, materials that are acceptable for use by workers in a controlled manufacturing setting may be unacceptable if the facility is repurposed for commercial or residential use. INDUSTRIAL PROPERTY REDEVELOPMENT Once an industrial facility is decommissioned, it may be demolished and the former industrial property redeveloped for non-industrial uses. Chemical concentrations in underlying soil and groundwater once deemed acceptable for an industrial site may not meet regulatory requirements for residential use. Industrial hygienists may be involved with remediation or mitigation to clean up the environmental media so that they are protective for these alternative uses. 
Potential exposure pathways include dermal contact and the inadvertent ingestion of chemicals in soil, groundwater, produce, and livestock through agricultural use of the land. Other potential pathways for exposure include inhalation of ambient air associated with the volatilization of chemicals from soil and fugitive dusts, and inhalation of indoor air after off-gassing within an existing structure or chemical vapor migration and intrusion into structures. 
During redevelopment of industrial property, multi-pathway risk assessments are typically conducted under the oversight of various environmental agencies to establish applicable cleanup criteria or measures intended to mitigate exposures. The requirements for remediation or mitigation are based on a comparison of acceptable risk thresholds to the estimated health risks. NEW ROLES Industrial hygienists will find that they can take on alternate roles as part of multi-disciplinary teams. These new roles will allow them to transfer their knowledge and expertise to new areas and affect decisions across the product and manufacturers’ business life cycle.
The majority opinion in Industrial Union Department, AFL-CIO, v. American Petroleum Institute et. al. read:
"If ... the odds are one in a billion that a person will die from cancer by taking a drink of chlorinated water, the risk clearly could not be considered significant. On the other hand, if the odds are one in a thousand that regular inhalation of gasoline vapors that are 2% benzene will be fatal, a reasonable person might well consider the risk significant."
An article in the AIHA 75th Anniversary supplement to the September 2014 Synergist that discusses the one-in-a-thousand risk benchmark for OSHA's Permissible Exposure Limits is available in the Synergist archives on the AIHA website (login required).
Editor's note: The original wording of this sentence, which appears in the print version of this article, implies that the author has knowledge of a specific scenario where leukemia was attributed to pumping gas. The sentence has been edited here to better convey the author's intent.