EPA Takes “Three Important Steps” Intended to Ensure Chemical Safety

On June 1, 2018, the U.S. Environmental Protection Agency (EPA) announced that it took “three important steps” intended to ensure chemical safety under the Frank R. Lautenberg Chemical Safety for the 21st Century Act (Lautenberg Act), which amended the Toxic Substances Control Act (TSCA). EPA released the following for public comment: (1) the first ten problem formulation documents, (2) EPA’s systemic review approach document, and (3) a significant new use rule (SNUR) proposal enabling EPA to prevent new uses of asbestos, “the first such action on asbestos ever proposed.” As noted below, the due dates for public comments on the documents will be available when EPA publishes them in the Federal Register.

On December 19, 2016, EPA published a list of the first ten chemicals selected for review under the Lautenberg Act -- asbestos, 1-bromopropane (1-BP), carbon tetrachloride, 1,4-dioxane, cyclic aliphatic bromide cluster (HBCD), methylene chloride, n-methylpyrrolidone (NMP), perchloroethylene, C.I. Pigment Violet 29, and trichloroethylene (TCE). In June 2017, EPA published the scope of the risk evaluations to be conducted for these first ten chemical substances, including the hazards, exposures, conditions of use, and potentially exposed or susceptible subpopulations (PESS) that EPA expects to consider. In May, EPA published a response to comments document (Response to Comments) that addresses cross-cutting comments submitted in response to the scope documents for these ten chemical substances. It addresses comments that may be applicable to issues impacting all ten chemicals. EPA notes that the responses in the document represent its “preliminary reactions to some of the comments received, as the Agency has not reached final decisions on the approaches to the 10 risk evaluations.”

EPA describes the problem formulation documents released on June 1, 2018, as “an important interim step prior to completing and publishing the final risk evaluations by December 2019.” The problem formulation documents clarify the chemical uses that EPA expects to evaluate and describe how EPA expects to conduct the evaluations. Comments on the problem formulation documents will be due in 45 days upon publication in the Federal Register.

Each of the problem formulation documents notes that TSCA Section 6(b)(4)(D) requires EPA to publish the scope of the risk evaluation to be conducted, including the hazards, exposures, conditions of use and PESS that the Administrator expects to consider. Each of EPA’s scope documents published in June 2017 explains that because there was insufficient time for EPA to provide an opportunity for comment, as EPA intends to do for future scope documents, EPA is publishing and taking public comment on the problem formulation documents to refine the current scope, as an additional interim step prior to publication of the draft risk evaluations. Comments received on the problem formulation documents will inform development of the draft risk evaluation.

According to the problem formulation document for asbestos, EPA has identified the ongoing use of chrysotile asbestos in: industrial processes in the chlor-alkali industry; asbestos sheet gaskets for use in equipment used in the manufacture of titanium dioxide; and asbestos brake blocks in oilfield equipment and aftermarket asbestos brake linings. In addition, certain asbestos-containing products can be imported into the U.S., but the amounts are not known. These products are mostly used in industrial processes (e.g., cement products) but could also be used by consumers, and include woven products and automotive brakes and linings. EPA is excluding legacy uses, associated disposals, and legacy disposals from the problem formulation and risk evaluation, as it did in the scope document. EPA states that it is excluding these activities “because EPA generally interprets the mandates under section TSCA § 6(a)-(b) to conduct risk evaluations and any corresponding risk management to focus on uses for which the manufacture, processing or distribution is intended, known to be occurring, or reasonably foreseen, rather than reaching back to evaluate the risks associated with legacy uses, associated disposal, and legacy disposal, and interprets the definition of conditions of use in that context.”

In previous Integrated Risk Information System (IRIS) assessments, EPA identified asbestos as a carcinogen causing both lung cancer and mesothelioma from inhalation exposures and derived a unit risk to address both cancers. According to the problem formulation, “[g]iven the well-established carcinogenicity of asbestos for lung cancer and mesothelioma, EPA decided to limit the scope of its systematic review to these two specific cancers with the goal of updating, or reaffirming, the existing cancer unit risk.” EPA will evaluate the inhalation hazards based on the specific exposure scenarios identified for workers, consumers, and the general population where applicable.

EPA has created a web page regarding its risk evaluation of asbestos. Materials are available there and in Docket EPA-HQ-OPPT-2016-0736.

The problem formulation document for 1-BP states that 1-BP is primarily used as a solvent cleaner in vapor and immersion degreasing operations to clean optics, electronics, and metals, but it has also been reported to be used as an alternative to ozone-depleting substances and chlorinated solvents, as a solvent vehicle in industries using spray adhesives such as foam cushion manufacturing, and in the dry cleaning industry. Information from the 2016 Chemical Data Reporting (CDR) for 1-BP indicates the reported production volume is 25.9 million pounds per year (manufacture and import). According to EPA, exposures to workers, consumers, and/or the general population may occur from industrial, commercial, or consumer uses of 1-BP and industrial releases to air, water, or land. Workers and occupational non-users (ONU) (i.e., workers who do not directly handle the chemical but perform work in an area where the chemical is used) may be exposed to 1-BP during a variety of conditions of use such as manufacturing, processing, distribution, repackaging, spray adhesives, dry cleaning (including spot cleaning), and degreasing (vapor, cold cleaning, and aerosol). Consumers and bystanders (non-product users that are incidentally exposed to the product) may be exposed to 1-BP from various consumer uses such as aerosol and spray adhesives, aerosol spot removers, and aerosol cleaning and degreasing products. For 1-BP, EPA states that it considers workers, ONUs, consumers, bystanders, and certain other groups of individuals who may experience greater exposures than the general population due to proximity to conditions of use to be PESS. Exposures to the general population may occur from industrial and/or commercial uses; industrial releases to air, water, or land; and other conditions of use. EPA will evaluate whether groups of individuals within the general population may be exposed via pathways that are distinct from the general population due to unique characteristics (e.g., life stage, behaviors, activities, or duration) that increase exposure and whether groups of individuals have heightened susceptibility and should, therefore, be considered PESS for purposes of the risk evaluation.

EPA plans to analyze further inhalation exposures to vapors and mists for workers and ONUs and dermal exposures for skin contact with liquids in occluded situations for workers in the risk evaluation. EPA plans to analyze further inhalation exposures to vapors and mists for consumers and bystanders and dermal exposures for skin contact with liquids in the risk evaluation. According to the problem formulation, for environmental release pathways, EPA does not plan to analyze further surface water exposure to aquatic invertebrates and aquatic plants in the risk evaluation.

EPA has created a web page regarding its risk evaluation of 1-BP. Materials are available there and in Docket EPA-HQ-OPPT-2016-0741.

According to the problem formulation document for carbon tetrachloride, currently it is used as a feedstock in the production of hydrochlorofluorocarbons (HCFC), hydrofluorocarbons (HFC), and hydrofluoroolefins (HFO). EPA has identified information on the regulated use of carbon tetrachloride as a process agent in the manufacturing of petrochemicals-derived and agricultural products and other chlorinated compounds such as chlorinated paraffins, chlorinated rubber, and others that may be used downstream in the formulation of solvents for degreasing and cleaning, adhesives, sealants, paints, coatings, rubber, cement, and asphalt formulations. The use of carbon tetrachloride for non-feedstock uses (i.e., process agent, laboratory chemical) is regulated in accordance with the Montreal Protocol.

Recent data on environmental releases from the Toxics Release Inventory (TRI) indicate that approximately 153,000 pounds of carbon tetrachloride were released to the environment in 2015. Most of the reported environmental releases for carbon tetrachloride were air emissions (fugitive and point source air emissions).

EPA states that exposure may occur through inhalation and oral and dermal pathways “due to carbon tetrachloride’s widespread presence in a variety of environmental media such as air, drinking water, groundwater, and surface water.” Exposures to the general population may occur from industrial, and/or commercial uses; industrial releases to air, water, or land; and other conditions of use. Workers and ONUs may be exposed to carbon tetrachloride during a variety of conditions of use, such as manufacturing, processing, and industrial and commercial uses, including manufacturing of refrigerants and other chlorinated compounds. According to EPA, it expects that the highest exposures to carbon tetrachloride generally involve workers in industrial and commercial settings. EPA considers workers and ONUs to be PESS. EPA will evaluate whether groups of individuals may be exposed via pathways that are distinct due to unique characteristics that increase exposure and whether groups of individuals have heightened susceptibility and should, therefore, be considered PESS for purposes of the risk evaluation.

EPA has created a web page regarding its risk evaluation of carbon tetrachloride. Materials are available there and in Docket EPA-HQ-OPPT-2016-0733.

The problem formulation document for 1,4-dioxane states that it is currently used in industrial processes and for industrial and commercial uses. Industrial processing uses include use as a processing aid and in functional fluids in open and closed systems. 1,4-Dioxane has uses as a laboratory chemical reagent, in adhesives and sealants, and several other identified uses. Historically, 90 percent of 1,4-dioxane produced was used as a stabilizer in chlorinated solvents such as 1,1,1-trichloroethane (TCA). Use of 1,4-dioxane has decreased since TCA was phased out by the Montreal Protocol in 1996.

The most recent data on environmental releases, according to TRI, indicate that approximately 675,000 pounds of 1,4-dioxane were released to the environment in 2015. Releases are reported to all types of environmental media: air, water, and land. The environmental fate of 1,4-dioxane is characterized by partitioning to the atmosphere, surface water, and groundwater, and degradation by atmospheric oxidation or biodegradation. It is expected to be moderately persistent in the environment and has a low bioaccumulation potential.

Workers and ONUs may be exposed to 1,4-dioxane during industrial and commercial conditions of use such as manufacturing, processing, distribution, use, and disposal. EPA plans to analyze further inhalation exposures to vapors and mists for workers and ONUs and dermal exposures for skin contact with liquids in occluded situations for workers in the risk evaluation. For environmental release pathways, EPA plans to include surface water exposure to aquatic vertebrates, invertebrates, and aquatic plants, exposure to sediment organisms, and exposure to 1,4-dioxane in land-applied biosolids in the risk evaluation.

EPA has created a web page regarding its risk evaluation of 1,4-dioxane. Materials are available there and in Docket EPA-HQ-OPPT-2016-0723.

According to the problem formulation document for HBCD, its primary use is as a flame retardant in expanded polystyrene (EPS) foam and extruded polystyrene (XPS) foam in the building and construction industry for thermal insulation boards and foam insulation panels. HBCD also has limited use in replacement parts for automobiles. Past uses of HBCD have included use in HIPS (high impact polystyrene) and textiles. EPA states that information gathered from research, industry, and consumer product organizations, however, led it to conclude that those past uses are not ongoing; there is no longer manufacture, processing, or distribution of HBCD for HIPS or textiles; therefore, those uses are not included in the scope of the risk evaluation of HBCD.

With the listing of HBCD as a persistent organic pollutant under the Stockholm Convention in 2013, industry began to phase out the manufacture and use of HBCD. In recent years, domestic manufacture of HBCD has ceased. Some HBCD was imported in 2017, and EPA states that it believes that a small amount of import may be ongoing. Use of stockpiles and exportation from the U.S. was completed at the end of 2017. EPA concluded that the import and processing of HBCD for use in EPS and XPS in buildings may be ongoing.

According to EPA, the conditions of use of EPS and XPS building insulation are within the scope of the evaluation and are anticipated to continue to contribute to exposures in indoor environments. In indoor environments, there may also be exposures resulting from legacy uses of HBCD in articles (textiles, electronics, and electrical products) containing HBCD. EPA expects these exposures to decline over time as use of these articles is phased out. The time scales for this are dependent on the age of the products, their useful service lives, and time lines for replacement.

While EPA expects environmental exposures to decline as the importing and processing of HBCD are phased out, based on past production volumes (millions of pounds per year) and the only recent cessation of domestic manufacturing, EPA states that “reductions in environmental concentrations will occur gradually over a period of time for this persistent and bioaccumulative compound.”

According to EPA, exposures to workers, consumers, and/or the general population may occur from industrial, commercial, and consumer uses of HBCD and releases to air, water, or land. Workers and ONUs may be exposed to HBCD during conditions of use such as import, processing, distribution, repackaging, and recycling. Consumers and bystanders may also be exposed to HBCD via inhalation of particulates, dermal contact with HBCD in articles, and oral exposure via ingestion of settled dust. Exposures to the general population may occur from industrial releases related to the import, processing, distribution, and use of HBCD. For HBCD, EPA considers workers, ONUs, consumers, bystanders, and certain other groups of individuals who may experience greater exposures than the general population due to proximity to conditions of use to be PESS. EPA states that it will evaluate whether groups of individuals within the general population may be exposed via pathways that are distinct from the general population due to unique characteristics that increase exposure and whether groups of individuals have heightened susceptibility and should, therefore, be considered PESS subpopulations for purposes of the risk evaluation.

For aquatic ecological receptors, EPA states that it expects sediment-dwelling benthic species to be exposed to HBCD. Exposures to pelagic species are also expected from HBCD present in surface water. Trophic magnification may result in greater exposure following bioaccumulation. According to EPA, it expects that aquatic and terrestrial species will be exposed to HBCD through the dietary exposure pathway. EPA will consider which aquatic and terrestrial species are related via the food chain.

EPA has created a web page regarding its risk evaluation of HBCD. Materials are available there and in Docket EPA-HQ-OPPT-2016-0735.

The problem formulation document for methylene chloride states that methylene chloride, also known as dichloromethane and DCM, “is a volatile and high production volume (HPV) chemical that is used as a solvent in a wide range of industrial, commercial and consumer applications.” In 2015, more than 260 million pounds of methylene chloride was reported to be manufactured (including imported) in the U.S. The primary uses for methylene chloride are paint stripping and removal (30 percent), adhesives (22 percent), pharmaceuticals (11 percent), metal cleaning (eight percent), aerosols (eight percent), chemical processing (eight percent), flexible polyurethane foam (five percent), and miscellaneous (eight percent).

Exposures may occur to workers, ONUs, consumers, bystanders, and the general population through inhalation, dermal, and oral pathways. Workers and ONUs may be exposed to methylene chloride during a variety of conditions of use, such as manufacturing, processing, and industrial and commercial uses, including uses in paint removal, adhesives, and degreasing. EPA states that it expects that the highest exposures to methylene chloride generally involve workers in industrial and commercial settings. Methylene chloride can be found in numerous products and can, therefore, result in exposures to commercial and consumer users in indoor or outdoor environments. For methylene chloride, EPA considers workers, ONUs, consumers, bystanders, and certain other groups of individuals who may experience greater exposures than the general population due to proximity to conditions of use to be PESS. Exposures to the general population may occur from industrial and/or commercial uses; industrial releases to air, water, or land; and other conditions of use. EPA will evaluate whether groups of individuals within the general population may be exposed via pathways that are distinct from the general population due to unique characteristics that increase exposure and whether groups of individuals have heightened susceptibility and should, therefore, be considered PESS for purposes of the risk evaluation. EPA plans to analyze further inhalation exposures to vapors and mists for workers and ONUs and dermal exposures for skin contact with liquids in occluded situations for workers in the risk evaluation. EPA plans also to analyze further inhalation exposures to vapors and mists for consumers and bystanders and dermal exposures for skin contact with liquids in the risk evaluation. For environmental release pathways, EPA plans to analyze further surface water exposure to aquatic invertebrates and aquatic plants in the risk evaluation.

EPA has created a web page regarding its risk evaluation of methylene chloride. Materials are available there and in Docket EPA-HQ-OPPT-2016-0742.

The problem formulation document for NMP states that it is an HPV chemical that is widely used during the manufacture and production of polymers, pharmaceuticals, agrichemicals, and petroleum products. In 2015, more than 160 million pounds of NMP was reported to be manufactured (including imported) in the U.S. According to a recent EPA market report, the primary uses for NMP include petrochemical processing, engineering plastic coatings, electronics, pharmaceutical and agrichemical manufacturing, and solvent cleaning.

Exposures may occur to workers and ONUs, consumers, bystanders, and members of the general population. Workers and ONUs may be exposed to NMP during various conditions of use (e.g., manufacturing, processing, and industrial/commercial uses). General population exposures may result from industrial and/or commercial uses; industrial releases to air, water, or land; and other conditions of use. EPA states that it expects the highest exposures will generally involve workers in industrial and commercial settings. EPA notes that NMP occurs in numerous consumer products, however, and can result in exposures outside the occupational setting. EPA considers workers, ONUs, consumers, bystanders, and certain other groups of individuals who may experience greater exposures than the general population to be PESS. During the risk evaluation, EPA expects to analyze further inhalation exposures to NMP vapor and mist (for workers, ONUs, consumers, and bystanders). EPA also expects to analyze dermal exposures from direct contact with NMP-containing liquids (for workers and consumers) and indirect exposure from vapor-through-skin contact (for workers, ONUs, consumers, and bystanders).

EPA has created a web page regarding its risk evaluation of NMP. Materials are available there and in Docket EPA-HQ-OPPT-2016-0743.

According to the problem formulation document for perchloroethylene, perchloroethylene is an HPV solvent. According to the 2016 CDR, more than 324 million pounds of perchloroethylene were manufactured (including imported) in the U.S. in 2015. Perchloroethylene is primarily used to produce fluorinated compounds, such as HFCs and HCFCs (65 percent) followed by dry cleaning (15 percent) and vapor degreasing solvents (ten percent). Other uses can be quite varied, including: adhesives; degreasing; brake cleaner; laboratories; lubricants; mold cleaners, releases, and protectants; oil refining; sealants; stainless steel polish; tire buffers and cleaners; and vandal mark removers.

Exposures may occur to workers, ONUs, consumers, bystanders, and the general population through inhalation, dermal, and oral pathways. Workers and ONUs may be exposed to perchloroethylene during a variety of conditions of use, such as manufacturing, processing, and industrial and commercial uses, including uses in degreasing and adhesives. EPA states that it expects that the highest exposures to perchloroethylene generally involve workers in industrial and commercial settings. Perchloroethylene can be found in numerous products and can, therefore, result in exposures to commercial and consumer users in indoor or outdoor environments. For perchloroethylene, EPA considers workers, ONUs, consumers, bystanders, and certain other groups of individuals who may experience greater exposures than the general population due to proximity to conditions of use to be PESS. Exposures to the general population may occur from industrial and/or commercial uses; industrial releases to air, water, or land; and other conditions of use. EPA states that it will evaluate whether groups of individuals within the general population may be exposed via pathways that are distinct from the general population due to unique characteristics that increase exposure and whether groups of individuals have heightened susceptibility and should, therefore, be considered PESS for purposes of the risk evaluation. EPA plans to analyze further inhalation exposures to vapors and mists for workers and ONUs and dermal exposures for skin contact with liquids in occluded situations for workers in the risk evaluation. For environmental release pathways, EPA plans to analyze further surface water exposure to aquatic vertebrates, invertebrates, and aquatic plants and exposure to sediment-dwelling organisms.

EPA has created a web page regarding its risk evaluation of perchloroethylene. Materials are available there and in Docket EPA-HQ-OPPT-2016-0732.

The problem formulation document for C.I. Pigment Violet 29 states that it is an organic pigment found in the following uses: (1) colorant primarily in paints and coatings, plastics, and rubber products, and merchant ink for commercial printing; (2) intermediate to create or adjust the color of other perylene pigments; (3) formulation, mixture, or reaction product; and (4) consumer watercolor and artistic color.

According to EPA, analysis of manufacturing conditions, uses, and engineering controls of C.I. Pigment Violet 29 indicates that releases from manufacturing, processing, distribution, use, and disposal are expected to be limited. Physical-chemical characteristics (i.e., low vapor pressure, low water solubility, high sorption to organic matter, high molecular weight, high Log Kow) indicate exposures would be limited if C.I. Pigment Violet 29 is released to the environment.

EPA states that based on limited releases, low potential for environmental and human exposures, and a low toxicity profile for mammals and aquatic species, it concludes that further analysis of these exposure pathways to workers, consumers, the general population, and environmental receptors is not warranted for C.I. Pigment Violet 29.

EPA has created a web page regarding its risk evaluation of C.I. Pigment Violet 29. Materials are available there and in Docket EPA-HQ-OPPT-2016-0725.

According to the problem formulation document for TCE, TCE is a volatile organic liquid that is classified as a human carcinogen. In the 2014 TCE risk assessment, EPA assessed inhalation risks from TCE in vapor and aerosol degreasing, spot cleaning at dry cleaning facilities, and arts and craft uses, and also completed four supplemental analyses. Based on these analyses, EPA notes that it published two proposed rules to address the risks presented by TCE use in vapor degreasing and in commercial and consumer aerosol degreasing and for spot cleaning at dry cleaning facilities.

Information on domestic manufacture, processing, use, and disposal of TCE is available to EPA through CDR and TRI. In 2015, approximately 172 million pounds of TCE was manufactured or imported in the U.S. An estimated 83.6 percent of TCE’s annual production volume is used as an intermediate in the manufacture of HFC-134a -- an alternative to the refrigerant CFC-12. Another 14.7 percent of TCE production volume is used as a degreasing solvent, leaving approximately 1.7 percent for other uses, including consumer uses. Based on 2015 TRI data, most reported environmental releases of TCE are to air, with much lower volumes disposed to land or released to water. According to EPA, TCE is expected to be moderately persistent in the environment and has a low bioaccumulation potential.

Exposure may occur through inhalation, oral, and dermal pathways, due to TCE’s widespread presence in a variety of environmental media. Exposures to the general population may occur from industrial and/or commercial uses; industrial releases to air, water, or land; and other conditions of use. Workers and ONUs may be exposed to TCE during a variety of conditions of use, such as manufacturing, processing, and industrial and commercial uses, including uses in paint and coatings, adhesives, and degreasing. EPA states that it expects that the highest exposures to TCE generally involve workers in industrial and commercial settings. TCE can be found in numerous products and can, therefore, result in exposures to commercial and consumer users in indoor or outdoor environments. For TCE, EPA considers workers, ONUs, consumers, bystanders, and certain other groups of individuals who may experience greater exposures than the general population due to proximity to conditions of use to be PESS. EPA will evaluate whether groups of individuals within the general population may be exposed via pathways that are distinct from the general population due to unique characteristics that increase exposure and whether groups of individuals have heightened susceptibility and should, therefore, be considered PESS for purposes of the risk evaluation. For environmental release pathways, EPA plans to analyze further surface water exposure to aquatic species (i.e., aquatic plants) in the risk evaluation.

EPA has created a web page regarding its risk evaluation of TCE. Materials are available there and in Docket EPA-HQ-OPPT-2016-0737.

EPA states that its systematic review approach document will guide its selection and review of studies in addition to providing the public with continued transparency regarding how EPA plans to evaluate scientific information. The internal guidance document sets out general principles to guide EPA’s application of systematic review in the risk evaluation process for the first ten chemicals, as well as future evaluations. Comments on the systematic review approach document will be due in 45 days upon publication in the Federal Register.

The Office of Pollution Prevention and Toxics (OPPT) plans to implement a structured process of identifying, evaluating, and integrating evidence for both the hazard and exposure assessments developed during the TSCA risk evaluation process. As OPPT expects that new approaches and/or methods will be developed to address specific assessment needs for the relatively large and diverse chemical space under TSCA, OPPT intends to document the progress of implementing systematic review in the draft risk evaluations and through revisions of this document and publication of supplemental documents.

The systematic review approach document provides only the general expectations for evidence synthesis and integration. Additional details on the approach for the evidence synthesis and integration will be included with the publication of the draft TSCA risk evaluations. EPA states that “[‌u]ltimately, the goal is to establish an efficient systematic review process that generates high-quality, fit-for-purpose risk evaluations that rely on the best available science and the weight of the scientific evidence within the context of TSCA.”

EPA intends the information and procedures set forth in the document to be a technical resource to those conducting TSCA risk evaluations for existing chemicals. EPA notes that non-mandatory language such as “should” provides recommendations and does not impose any legally binding requirements. Similarly, “statements about what EPA expects or intends to do reflect general principles to guide EPA’s activities and not judgments or determinations as to what EPA will do in any particular case.” According to EPA, the document is not necessarily applicable to risk assessments developed to support other EPA statutes or programs. EPA expects to make changes to the living document at any time and, therefore, may periodically revise the document.

EPA described its initial work on systematic review in the supplemental files for each TSCA scope document, which included the Strategy for Conducting Literature Searches and the Bibliography for each chemical. EPA has posted its Response to Comments received on these supplemental documents.

For asbestos, EPA will propose a SNUR for certain uses of asbestos (including asbestos-containing goods) that would require manufacturers and importers to receive EPA approval before starting or resuming manufacturing and importing or processing of asbestos. This review process would provide EPA with the opportunity to evaluate the intended use of asbestos and, when necessary, take action to prohibit or limit the use. EPA has published a pre-publication version of the Federal Register notice. Comments on the proposed SNUR will be due in 60 days upon publication in the Federal Register.

The notice states that the proposed significant new use of asbestos (including as part of an article) is manufacturing (including importing) or processing for certain uses identified by EPA as no longer ongoing. According to the notice, EPA has found no information indicating that the following uses are ongoing, and therefore, the following uses are subject to the proposed SNUR: adhesives, sealants, and roof and non-roof coatings; arc chutes; beater-add gaskets; extruded sealant tape and other tape; filler for acetylene cylinders; high-grade electrical paper; millboard; missile liner; pipeline wrap; reinforced plastics; roofing felt; separators in fuel cells and batteries; vinyl-asbestos floor tile; and any other building material (other than cement).

Persons subject to the SNUR would be required to notify EPA at least 90 days before commencing any manufacturing (including importing) or processing of asbestos (including as part of an article) for a significant new use. The required notification initiates EPA’s evaluation of the conditions of use associated with the intended use within the applicable review period. Manufacturing (including importing) and processing (including as part of an article) for the significant new use may not commence until EPA has conducted a review of the notice, made an appropriate determination on the notice, and taken such actions as are required in association with that determination.

In EPA’s cross-cutting Response to Comments, EPA makes a number of key points that apply across all ten problem formulation documents and that we expect will inform future TSCA existing chemicals risk evaluation work. EPA acknowledges that the ten scoping documents were not as detailed as expected, largely due to the very short timeframe available to complete each. As such, EPA is refining the scope of each in the problem formulation documents. EPA expects future scoping documents to be more robust, necessitating less revisions of the scope in future problem formulation documents.

EPA responds to comments related to conditions of use by reiterating that it will generally not consider misuse and off-label uses or “legacy” uses as conditions of use. EPA points to the legislative history and the statutory language to support its view that conditions of use are “intended, known to be occurring, or reasonably foreseen to occur (i.e., is prospective or on-going).” EPA also states that it will consider exposures from legacy uses on a case-by-case basis. For example, EPA is excluding past use as a fuel additive from the conditions of use evaluated in the 1,4-dioxane risk evaluation. 1,4-Dioxane was used as a fuel additive in the past and EPA only found evidence that it was phased out from that use and no evidence of on-going use as a fuel additive. Similarly, EPA found no current consumer uses of 1,4-dioxane, so is excluding consumer exposures from the risk evaluation. While these uses will not be considered in the risk evaluation, EPA may opt to issue a SNUR banning such uses absent submission of a significant new use notice (SNUN) and EPA taking the necessary action under TSCA Section 5(e) or 5(f). According to EPA, it can better focus its effort on active uses and protect against unreasonable risk in other potential uses during a review of a potential new use just as if 1,4-dioxane were a new chemical.Some stakeholders argue that EPA is not permitted to omit such a use from its risk evaluation, and that promulgating a SNUR prohibiting a use that is not on-going, but is otherwise reasonably foreseeable, effectively makes that use not reasonably foreseeable. The SNUR would prohibit that use just as a TSCA Section 6 risk management might. In this way, EPA can effectively limit its risk evaluation and simultaneously be fully protective against future uses that were outside the scope of the risk evaluation. This strikes us as an effective way for EPA efficiently to manage potential risks without undue effort evaluating speculative uses.

EPA also reiterated its view that it may exclude risks that are appropriately and adequately regulated under other authorities administered by either EPA or other Departments or Agencies. Along the same vein, EPA responds to a comment related to ozone depletion potential (ODP) by pointing out that ODP is evaluated and effectively managed under the Clean Air Act. In the 1,4-dioxane problem formulation document, EPA states that it views commercial and industrial air emissions of 1,4-dioxane as adequately managed as a Hazardous Air Pollutant under the Clean Air Act and will exclude risk to the general population from such emissions from the TSCA risk evaluation. Similarly, because 1,4-dioxane concentrations are already being monitored under the Safe Drinking Water Act, EPA will exclude general population exposures via drinking water from its risk evaluation. On the other hand, because EPA has yet to develop an ambient water quality standard for 1,4-dioxane under CWA 304(a), EPA will include risk to aquatic life in its risk evaluation. EPA also stated that it may exclude presence as an impurity from the scope of the risk evaluation if EPA has a basis to foresee that the risk from the impurity would be de minimis or otherwise insignificant.

EPA states that it will describe whether aggregate or sentinel exposures were considered and will include its explanation in the risk evaluation. In conducting an aggregate exposure, EPA may include exposures from non-TSCA uses. For example, in the 1,4-dioxane problem formulation, EPA included uses that are regulated under the Federal Food, Drug, and Cosmetic Act (FFDCA). EPA also intends to evaluate uses of 1,4-dioxane that might otherwise be eligible for the TSCA Research and Development (R&D) exemption. EPA will also include potential exposure to 1,4-dioxane from volatilization that might occur during showering or bathing.

In referring to the scope of the risk evaluation, EPA uses some language that may be somewhat confusing. For example, in Section 2.5.3.1 of the 1,4-dioxane problem formulation document, EPA states that there are “no environmental release and waste pathways for the environment or general population that EPA plans to include and further analyze in the risk evaluation.” Given that EPA specifically states that it will evaluate general population and environmental effects elsewhere in the document, we interpret the statement in Section 2.5.3.1 to mean that there are no additional pathways that EPA intends to include. Similarly, in Section 2.5.3.2, EPA states that “[t]he pathways that EPA plans to include in the risk evaluation but not further analyze are ambient water exposures to aquatic vertebrates, invertebrates and aquatic plants, sediment and land-applied biosolids.” Although EPA states that it does not intend to “further analyze” such exposures, EPA must mean that it is satisfied that the conceptual model that has already been identified is sufficient for the risk evaluation.

EPA does a good job in striking an excellent balance between the evaluation of all possible hazards and exposures to health and the environment and those for which (1) there is not otherwise adequate control; and (2) that are reasonably likely to occur above negligible levels. In this way, EPA will make the most efficient use of its effort and limited resources under TSCA to protect health and the environment and avoid extensive time and resources to collect and analyze information that will be, at best, of marginal use in informing a risk decision. EPA seeks input from stakeholders on all ten risk evaluations.