The EPA states that for the purposes of scoping and risk assessment, it has adopted the definition of asbestos as defined in Section 202 of the Toxic Substances Control Act (TSCA) as “asbestos varieties of six fibers – chrysotile (serpentine), crocidolite (rebequite), amosite (komingonite-gronirite), anthophyllite, tremolite, or actinolite.” The last five fiber types are types of amphibole. According to the EPA, since Part 2 of the risk assessment will focus on ancient uses of asbestos and associated disposals, “a unique consideration would be vermiculite, which has been widely used in building materials in the past and co-located with Libby amphibole asbestos (LAA; its components tremolite, winchite, and richterite).” The EPA will consider LAA and its components tremolite, winchite, and richterite in Part 2 of its risk assessment. The Environmental Protection Agency notes that another substance extracted from commercial mines, talc, has been implicated as a potential source of asbestos exposure. Talc can also be set geologically with asbestos, as asbestos can remain in small or trace amounts after extraction. Thus, the Environmental Protection Agency will determine the relevant terms for the use of talc, including but not limited to any “old use” and “associated disposal” where asbestos is involved.
The draft scope states that the EPA plans to assess releases to the environment, as well as human and environmental exposures from asbestos use conditions that the EPA plans to consider in a Part II risk assessment. Additional information collected through systematic review searches will also inform expected exposures. Tentatively, the EPA plans to evaluate the following human and environmental exposure pathways, routes, receptors, and PESS within the scope of the Part 2 risk assessment:
Occupational exposure: The EPA plans to assess exposure to workers and non-user (ONU) workers by inhalation, dermal, and oral route associated with asbestos use and disposal, to include any conditions involved in the use of asbestos-containing talc. The Environmental Protection Agency plans to analyze the skin exposure of workers and ONUs to fibers deposited on surfaces;
Consumer and Bystander Exposure: The EPA plans to assess inhaled, dermal, and oral exposure to asbestos for consumers and bystanders from asbestos use in construction, paint, electrical and metal products; asbestos in upholstery care, cleaning and treatment products; asbestos in packaging, paper, plastic, toys and hobby products; asbestos in automotive, fuel, agricultural and outdoor use products; asbestos in products not described in other codes; Direct and/or oral contact of asbestos-containing products or materials to consumers. In addition, any conditions involved in the use of talc containing asbestos will be evaluated;
General Population Exposure: For conditions of use within the scope of Part 2 of the Risk Assessment, the EPA plans to assess general population exposure to oral asbestos from drinking water, surface water, groundwater, and soil via the inhalation pathway of particulates in ambient air and through the skin 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 its risk assessment, as well as any other PESS identified in the examination and evaluation of reasonably available information; And
Environmental exposure: For conditions of use within the Part 2 scope, the EPA plans to assess exposure to asbestos for aquatic and terrestrial receptors.
EPA states that it plans to consider comments on the draft scope and other reasonably available information when finalizing the scope document, and to modify exposure pathways, exposure methods, hazards, and PESS included in the final scope document as needed.
The Scope Project is the first opportunity for stakeholders to evaluate the 2019 EPA interpretation Safer Chemicals, Healthy Families Against the EPA Court decision not to exclude “ancient uses” and “associated disposals” from the assessment of asbestos risks. Bergeson & Campbell, PC (B&C .)®) indicates that the EPA is conducting a Part 2 asbestos risk assessment using Draft Systematic Review Protocol Supporting TSCA Risk Assessments Released December 21, 2021.
As described above, Part 2 of the EPA’s asbestos risk assessment will include vermiculite and talc as well as amphibole fibers that are not included in Part 1. The EPA reports that “vermiculite, a mica-like mineral, is widely used in Building materials that will be the focus of a large part of the second part of the risk assessment.” Specifically, the Environmental Protection Agency intends to evaluate the vermiculite used in[c]Building and construction materials covering large areas of surfaces, including paper materials; metal objects; Products from stone, plaster, cement, glass and ceramics. “
With respect to talc, the Environmental Protection Agency will not consider conditions for use and evaluation of personal care products that may contain talc (for example , talcum powder and makeup), because such goods intended for use as medicine or cosmetics fall outside the TSCA definition of a “chemical”. The EPA will, however, assess the manufacture/import, distribution, industrial/commercial/consumer use and disposal of materials containing “asbestos-containing talc.” Commercial/consumer uses described in the draft scope (in another meaning, crayons and crime scene kits containing “asbestos-containing talc”) reflect the EPA’s intent to include children in the PESS assessment, another deviation from the approach taken in Part 1.
Another notable inclusion in the PESS assessment is “individuals who smoke”. It is generally known that smoking and asbestos interact synergistically, with smokers exposed to asbestos being more likely to develop lung cancer than non-smokers with similar levels of asbestos exposure. The public health implications are clear, however it remains to be seen whether the smoking status will be a legally and scientifically defensible basis for increased susceptibility under the TSCA.
The human health risk assessment in Part I focuses exclusively on cancer (in another meaning, Risk of lung cancer and mesothelioma) to workers and consumers via exposure to inhalation. In the draft scope, the EPA states that it will extend the Part II risk assessment to the general population, and include both cancerous and non-cancerous endpoints. via Exposure to inhalation, skin and mouth. The main outcome of the risk assessment in Part II will be the identification of risks for the general population. However, for workers and consumers, including non-cancer endpoints and additional exposure routes is just an exercise in completeness. Despite the speculation in Part I that the non-cancerous effects seen with LAA (for example , Asbestosis and pleural penetration) may occur at the same level as chrysotile fibers in carcinoma, and the reasonably available data are unlikely to find a more sensitive adverse effect than lung cancer and mesothelioma on which the risk assessment is based. Moreover, the physical and chemical properties of asbestos prevent skin absorption. The EPA’s assessment of oral exposure to asbestos is reflected in the maximum level of contaminants (in another meaning, 7 million fibers per liter). Based on the carcinogenic efficacy of asbestos that is intentionally ingested via Drink water for it via Inhalation exposure, accidental unintentional ingestion from the mouth is expected to be a minimal contributor to risk. However, B&C notes that this approach is more comprehensive and transparent than that presented in Part 1. Additionally, while including oral exposure is not amenable to pooling exposure analysis with inhaled exposure due to the nature of the portal effects of asbestos entry, the use of Total exposure provides stakeholders with a “risk cup” view and shows consistency across the Office of Chemical Safety and Pollution Prevention (OCSPP) given that the OPP routinely considers total (and cumulative) exposures in its assessments under the Federal Insecticide and Pesticide Act Fungi and Rodents (FIFRA).
Finally, the Scope Project details the literature review completed by the EPA to retrieve reasonably available information. The first part did not assess the risks to terrestrial organisms and did not find any unreasonable risks to the aquatic environment, due in large part to Toxic Release Inventory (TRI) data showing no chrysotile release into surface waters. However, EPA included no NOEC and LOEC for aquatic organisms in Part I, leaving the door open to unreasonable risks under different exposure conditions. The Scope project presents the results of an updated systematic review, including more than 100 citations for “environmental release” and nearly 300 search results for “exposure” (including ambient air, soil, surface water, aquatic species, and terrestrial species), so it is possible that The second part concludes that there is at least one unreasonable risk to the environment.
It remains to be seen how the EPA will calculate total exposures in occupational and residential settings. B&C considers that all stakeholders with data that may inform an updated exposure assessment to the EPA, such as monitoring data from asbestos processing projects or environmental monitoring, should bring this information to the agenda before February 14, 2022The deadline for the comment period.
Other TSCA stakeholders should continue to monitor the EPA’s update of the asbestos risk assessment and projected updates of the risk assessment for other “top ten” chemicals, as well as the “next 20” chemicals designated for assessments through the TSCA prioritization process, for further insight On how the EPA will implement Section 6 of the TSCA going forward.