REGULATORY MEMORANDUM

EPA Publishes Draft Scope of the Risk Evaluation for Asbestos Part 2: Supplemental Evaluation Including Legacy Uses and Associated Disposals of Asbestos

The U.S. Environmental Protection Agency (EPA) announced on December 29, 2021, the availability of the Draft Scope of the Risk Evaluation for Asbestos Part 2: Supplemental Evaluation Including Legacy Uses and Associated Disposals of Asbestos (Draft Scope). 86 Fed. Reg. 74088. In the Part 2 risk evaluation, EPA will evaluate the conditions of use of asbestos (including other types of asbestos fibers in addition to chrysotile) that EPA had excluded from Part 1 as legacy uses and associated disposals, as well as any conditions of use of asbestos in talc and talc-containing products. The Draft Scope includes the conditions of use, hazards, exposures, and the potentially exposed or susceptible subpopulations (PESS) that EPA plans to consider in conducting the risk evaluation for this chemical substance. EPA has opened a 45-day comment period on the Draft Scope to allow for the public to provide additional data or information that could be useful to EPA in preparing the final scope of the risk evaluation. Comments are due February 14, 2022.

In 2019, the court in Safer Chemicals Healthy Families v. EPA, 943 F.3d 397 (9th Cir. 2019) held that EPA’s risk evaluation rule should not have excluded “legacy uses” or “associated disposals” from the conditions of use. Following the court ruling, EPA continued development of the risk evaluation focused on chrysotile asbestos and determined that the complete risk evaluation for asbestos would be issued in two parts. As reported in our January 4, 2021, memorandum, EPA released the final risk evaluation for Asbestos, Part 1: Chrysotile Asbestos in December 2020, allowing EPA “to expeditiously move into risk management for the unreasonable risk identified in Part 1.” Under the consent decree in the case Asbestos Disease Awareness Organization et al v. Regan et al, 4:21-cv-03716 (N.D. Cal.), EPA is required to publish a final Part 2 Risk Evaluation for Asbestos on or before December 1, 2024. The Draft Scope of the Risk Evaluation for Asbestos Part 2 is the subject of this notice.

EPA states that for the purposes of scoping and risk evaluation, it adopted the definition of asbestos as defined by Title II of the Toxic Substances Control Act (TSCA) Section 202 as the “asbestiform varieties of six fiber types -- chrysotile (serpentine), crocidolite (riebeckite), amosite (cummingtonite-grunerite), anthophyllite, tremolite or actinolite.” The latter five fiber types are amphibole varieties. According to EPA, given that Part 2 of the risk evaluation will focus on legacy uses of asbestos and associated disposals, “a unique consideration will be vermiculite, which was widely used in building materials in the past and was co-located with Libby Amphibole Asbestos (LAA; and its tremolite, winchite, and richterite constituents).” EPA will consider LAA and its tremolite, winchite, and richterite constituents in Part 2 of the risk evaluation. EPA notes that another commercially mined substance, talc, has been implicated as a potential source of asbestos exposure. Talc can also be co-located geologically with asbestos, where asbestos can remain in small or trace amounts following extraction. Thus, EPA will determine the relevant conditions of use of talc, including but not limited to any “legacy use” and “associated disposal,” where asbestos is implicated.

According to the Draft Scope, EPA plans to evaluate the industrial, commercial, and consumer legacy uses and associated disposal of asbestos in Part 2 of the risk evaluation. EPA will be evaluating the conditions of use for the use and disposal phases of the life cycle. Depending on where information implicates the presence of asbestos in talc, the conditions of use may also include manufacture, processing, and distribution.

The Draft Scope states that EPA plans to evaluate releases to the environment, as well as human and environmental exposures resulting from the conditions of use of asbestos that EPA plans to consider in the Part 2 risk evaluation. Additional information gathered through systematic review searches will also inform expected exposures. Preliminarily, EPA plans to evaluate the following human and environmental exposure pathways, routes, receptors, and PESS in the scope of the Part 2 risk evaluation:

  • Occupational exposure: EPA plans to evaluate exposures to workers and occupational non-users (ONU) via the inhalation, dermal, and oral route associated with the use and disposal of asbestos, to include any implicated conditions of use for talc containing asbestos. EPA plans to analyze dermal exposure for workers and ONUs to fibers that deposit on surfaces;
     
  • Consumer and bystander exposure: EPA plans to evaluate inhalation, dermal, and oral exposure to asbestos for consumers and bystanders from the use of asbestos in construction, paint, electrical, and metal products; asbestos in furnishing, cleaning, and treatment care products; asbestos in packaging, paper, plastic, toys, and hobby products; asbestos in automotive, fuel, agriculture, and outdoor use products; and asbestos in products not described by other codes; and the direct contact and/or mouthing of products or articles containing asbestos for consumers. In addition, any implicated conditions of use for talc containing asbestos will be evaluated;
     
  • General population exposures: For the conditions of use within the scope of Part 2 of the risk evaluation, EPA plans to evaluate general population exposure to asbestos via the oral route from drinking water, surface water, groundwater, and soil via the inhalation route from particulate in ambient air; and via the dermal route from contact with drinking water, surface water, groundwater, and soil;
     
  • PESS: EPA plans to consider children, workers, ONUs, consumers, individuals who smoke, and bystanders as receptors and PESS in Part 2 of the risk evaluation, as well as any other PESS identified in the screening and evaluation of the reasonably available information; and
     
  • Environmental exposure: For the conditions of use within the scope of Part 2, EPA plans to evaluate exposure to asbestos for aquatic and terrestrial receptors.
     

EPA states that it plans to consider comments received on the Draft Scope and other reasonably available information when preparing the scope document in final, and to adjust the exposure pathways, exposure routes, hazards, and PESS included in the final scope document as needed.

Commentary

The Draft Scope is the first opportunity for stakeholders to evaluate EPA’s interpretation of the 2019 Safer Chemicals Healthy Families v. EPA court decision that “legacy uses” and “associated disposals” should not be excluded from the risk evaluation of asbestos. Bergeson & Campbell, P.C. (B&C®) notes that EPA is conducting Part 2 of the asbestos risk evaluation using the Draft Systematic Review Protocol Supporting TSCA Risk Evaluations for Chemical Substances released on December 21, 2021.

As described above, Part 2 of EPA’s asbestos risk evaluation will include vermiculite and talc in addition to the amphibole fibers that were not included in Part 1. EPA reports that “Vermiculite, a silicate, mica-like mineral, was widely used in building materials that will be a focus of much of Part 2 of the risk evaluation.” Specifically, EPA intends to evaluate vermiculite used in “[c]onstruction and building materials covering large surface areas, including paper articles; metal articles; stone, plaster, cement, glass, and ceramic articles.”

Regarding talc, EPA will not consider as conditions of use and evaluate personal care products that may contain talc (e.g., talcum powder and make-up), as such commodities intended for use as drugs or cosmetics fall outside the TSCA definition of “chemical substance.” EPA will evaluate, however, the manufacture/import, distribution, industrial/commercial/consumer use, and disposal of articles with “talc containing asbestos.” The commercial/consumer uses highlighted in the Draft Scope (i.e., crayons and toy crime scene kits with “talc containing asbestos”) reflect EPA’s intention to include children in its PESS evaluation, which is another deviation from the approach taken in Part 1.

Another notable inclusion in the PESS evaluation is “individuals who smoke.” It generally is known that smoking and asbestos interact synergistically, with smokers exposed to asbestos much more likely to develop lung cancer than non-smokers with similar levels of asbestos exposure. The public health implications are clear, yet it remains to be seen whether smoking status will be a legally and scientifically defensible basis for increased susceptibility under TSCA.

The human health hazard assessment in Part 1 exclusively focuses on cancer (i.e., combined lung cancer and mesothelioma) risk to workers and consumers via inhalation exposure. In the Draft Scope, EPA states that it will extend the Part 2 risk evaluation to the general population, and include both cancer and non-cancer endpoints via inhalation, dermal, and oral exposures. A key outcome of the Part 2 risk evaluation will be the risk determination for the general population. For workers and consumers, however, including non-cancer endpoints and additional routes of exposure is simply an exercise for the sake of completeness. Despite the speculation in Part 1 that the non-cancer effects seen with LAA (e.g., asbestosis and pleural thickening) may occur at the same level that chrysotile fibers cause cancer, reasonably available data are unlikely to find a more sensitive adverse effect than combined lung cancer and mesothelioma on which the risk evaluation is based. Further, the physicochemical properties of asbestos preclude dermal absorption. EPA’s evaluation of oral exposure to asbestos is reflected in the maximum contaminant level (i.e., 7 million fibers per liter). Based on the cancer potency of asbestos ingested intentionally via drinking water versus that via inhalation exposure, unintentional hand-to-mouth incidental ingestion is expected to be a negligible contributor to risk. B&C notes, however, that this approach is more thorough and transparent than that presented in Part 1. Additionally, while the inclusion of oral exposure is not amenable to aggregate exposure analysis with inhalation exposure because of the nature of the portal of entry effects of asbestos, the use of aggregate exposure provides stakeholders with a view of the “risk cup” and demonstrates consistency across the Office of Chemical Safety and Pollution Prevention (OCSPP) given that the Office of Pesticide Programs (OPP) routinely considers aggregate (and cumulative) exposure in its assessments under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

Finally, the Draft Scope details the literature review EPA completed to retrieve reasonably available information. Part 1 did not evaluate risk to terrestrial organisms and found no unreasonable risk to the aquatic environment, largely due to Toxics Release Inventory (TRI) data showing no release of chrysotile to surface water. Nevertheless, EPA did include No Observed-Effect Concentrations (NOEC) and Lowest Observed Effect Concentrations (LOEC) for aquatic organisms in Part 1, leaving the door to unreasonable risk open under different exposure conditions. The Draft Scope presents the results of the updated systematic review, including over 100 citations for “environmental release” and approximately 300 “exposure” search results (including ambient air, soil, surface water, aquatic species, and terrestrial species), so it is possible that Part 2 may conclude there is at least one unreasonable risk to the environment.

It remains to be seen how EPA will calculate aggregate exposures in occupational and residential settings. It is B&C’s view that all stakeholders in possession of data that may inform EPA’s updated exposure assessment, such as monitoring data from asbestos remediation projects or environmental monitoring, should submit that information to the docket prior to the February 14, 2022, comment period deadline.

Other TSCA stakeholders should continue to monitor EPA’s update to the asbestos risk evaluation and anticipated updates to the risk evaluations for the other “First 10” chemicals, as well as the “Next 20” chemicals designated for evaluations through the TSCA prioritization process, for further insight into how EPA will implement TSCA Section 6 going forward.

 
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