Toxic Substances Control Act Research Articles

US EPA’s proposed asbestos ban faces industry fight

US imports of chrysotile asbestos, used exclusively by the chlor-alkali industry, would be banned under a landmark rule proposed April 5 by the US Environmental Protection Agency . The rule would also prohibit importing asbestos in products such as sheet gaskets and automotive brake parts. The proposed ban marks the EPA’s first action to manage the risks of a high-priority chemical under the 2016 revisions to the Toxic Substances Control Act (TSCA). Asbestos, a human carcinogen, is one of the first 10 chemicals the EPA is scrutinizing under the amended law . Most uses of asbestos have been discontinued in the US, but chlor-alkali producers have long fought to keep using the substance in diaphragms that separate chlorine and sodium hydroxide. Ten chlor-alkali facilities in the US, or about one-third, still use asbestos-containing diaphragms, according to the EPA. But alternatives are available. Nearly half the US chlor-alkali industry uses fluoropolymer

Rethinking our chemical legacy and reclaiming our planet

Rethinking our chemical legacy and reclaiming our planet

Toxic Substances Control Act (TSCA) Implementation: New Ways to Promote Occupational Justice and Prevent Worker Exposures From Hazardous Chemicals.

Toxic Substances Control Act (TSCA) Implementation: New Ways to Promote Occupational Justice and Prevent Worker Exposures From Hazardous Chemicals.

Charting a Path Forward: Assessing the Science of Chemical Risk Evaluations under the Toxic Substances Control Act in the Context of Recent National Academies Recommendations.

Background:In 2016, Congress enacted the Frank R. Lautenberg Chemical Safety for the 21st Century Act (“the Lautenberg Act”), which made major revisions to the main U.S. chemical safety law, the 1976 Toxic Substances Control Act (TSCA). Among other reforms, the Lautenberg Act mandates that the U.S. Environmental Protection Agency (U.S. EPA) conduct comprehensive risk evaluations of chemicals in commerce. The U.S. EPA recently finalized the first set of such chemical risk evaluations.Objectives:We examine the first 10 TSCA risk evaluations in relation to risk science recommendations from the National Academies to determine consistency with these recommendations and to identify opportunities to improve future TSCA risk evaluations by further implementing these key approaches and methods.Discussion:Our review of the first set of TSCA risk evaluations identified substantial deviations from best practices in risk assessment, including overly narrow problem formulations and scopes; insufficient characterization of uncertainty in the evidence; inadequate consideration of population variability; lack of consideration of background exposures, combined exposures, and cumulative risk; divergent approaches to dose–response assessment for carcinogens and noncarcinogens; and a flawed approach to systematic review. We believe these deviations result in underestimation of population exposures and health risks. We are hopeful that the agency can use these insights and have provided suggestions to produce chemical risk evaluations aligned with the intent and requirements of the Lautenberg Act and the best available science to better protect health and the environment—including the health of those most vulnerable to chemical exposures. https://doi.org/10.1289/EHP9649

Researchers track potentially toxic chemical derivatives in city air

Flame-retardant chemicals found in city air around the world can transform into a soup of derivatives that are predicted to be more toxic and more persistent than their parent compounds. That’s the conclusion of a study of organophosphate ester flame retardants (OPFRs) that relies on a new framework for assessing the risks of commercial chemicals ( Nature 2021, DOI: 10.1038/s41586-021-04134-6 ). This three-step framework—which combines laboratory studies, environmental screening, and computer modeling—could be applied to other groups of mass-produced chemicals. Through reactions with light, oxygen, and other pathways, molecules in air can spawn a range of transformation products that may have properties that are very different from those of their parent. Yet these products are rarely factored into the risk assessments that underpin chemical regulation programs such as the US Toxic Substances Control Act (TSCA), often because so little is known about the derivatives. To address this, study coleader John

CSCL and Industrial Chemical Management Framework in Japan

Despite Japan’s presence in the global economy, its industrial chemical regulations were less accessible than other economies’ chemical regulation frameworks, such as the United States’ Toxic Substances Control Act (TSCA) and Europe’s Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH), due to the limited information in English. Since the Japanese government considered chemical regulations as domestic issues, it did not prioritize disseminating information to overseas stakeholders. This Case Study outlines Japan’s industrial chemical regulation framework and highlights the Chemical Substance Control Law (CSCL) by elaborating on its development history and amendments. The author was involved in CSCL implementation for more than 14 years.

US EPA to strengthen asbestos risk evaluation

In a win for environmental and public health groups, the US Environmental Protection Agency on Oct. 12 committed to broadening and speeding up its review of the health risks of asbestos under two legal settlements . Asbestos is one of the first 10 substances the EPA evaluated under the 2016 revisions to the Toxic Substances Control Act (TSCA). The agency released its final assessment Dec. 30, 2020, finding unreasonable risks to workers and consumers who handle many products containing asbestos, including chlor-alkali diaphragms the chemical industry uses to produce chlorine. But the EPA did not evaluate risks from legacy uses of asbestos, such as insulation and other construction materials that are still found in older buildings. The agency also did not consider all forms of asbestos and instead focused only on chrysotile, the type of asbestos imported into the US. The EPA said it would assess legacy uses in a

Integrating publicly available information to screen potential candidates for chemical prioritization under the Toxic Substances Control Act: A proof of concept case study using genotoxicity and carcinogenicity

The Toxic Substances Control Act (TSCA) became law in the U.S. in 1976 and was amended in 2016. The amended law requires the U.S. EPA to perform risk-based evaluations of existing chemicals. Here, we developed a tiered approach to screen potential candidates based on their genotoxicity and carcinogenicity information to inform the selection of candidate chemicals for prioritization under TSCA. The approach was underpinned by a large database of carcinogenicity and genotoxicity information that had been compiled from various public sources. Carcinogenicity data included weight-of-evidence human carcinogenicity evaluations and animal cancer data. Genotoxicity data included bacterial gene mutation data from the Salmonella (Ames) and Escherichia coli WP2 assays and chromosomal mutation (clastogenicity) data. Additionally, Ames and clastogenicity outcomes were predicted using the alert schemes within the OECD QSAR Toolbox and the Toxicity Estimation Software Tool (TEST).The evaluation workflows for carcinogenicity and genotoxicity were developed along with associated scoring schemes to make an overall outcome determination. For this case study, two sets of chemicals, the TSCA Active Inventory non-confidential portion list available on the EPA CompTox Chemicals Dashboard (33,364 chemicals, ‘TSCA Active List’) and a representative proof-of-concept (POC) set of 238 chemicals were profiled through the two workflows to make determinations of carcinogenicity and genotoxicity potential. Of the 33,364 substances on the ‘TSCA Active List’, overall calls could be made for 20,371 substances. Here 46.67%% (9507) of substances were non-genotoxic, 0.5% (103) were scored as inconclusive, 43.93% (8949) were predicted genotoxic and 8.9% (1812) were genotoxic. Overall calls for genotoxicity could be made for 225 of the 238 POC chemicals. Of these, 40.44% (91) were non-genotoxic, 2.67% (6) were inconclusive, 6.22% (14) were predicted genotoxic, and 50.67% (114) genotoxic. The approach shows promise as a means to identify potential candidates for prioritization from a genotoxicity and carcinogenicity perspective.

Comments from the perspective of pertinent committees of the US National Academies of Sciences

BACKGROUND AND AIM: This presentation will comment on the ISEE principles of evidence synthesis and evaluation in environmental health from the perspective of pertinent committees of the US National Academies of Sciences, Engineering, and Medicine (NASEM). METHODS: Over the last decade, beginning with the Review of the Environmental Protection Agency’s (EPA) Draft IRIS Assessment of Formaldehyde, multiple committees have addressed the role and conduct of systematic review within several distinct US regulatory frameworks, including those used under the Toxic Substances Control Act (TSCA) and the Integrated Risk Information System (IRIS). These committees have probed the details of how evidence is evaluated, synthesized, and integrated in these agency processes. RESULTS:One overarching finding is the lack of a set of harmonized approaches. Additionally, the EPA (and others) are challenged to develop approaches for systematic review for mechanistic and other toxicological research. CONCLUSIONS:Guidelines for principles of evidence evaluation and synthesis from ISEE could play a critical role as regulatory frameworks for using evidence continue to evolve; benchmarks are needed. KEYWORDS: principles, evidence synthesis, evaluation, environmental health

NACD Expresses Concerns with EPA TSCA Fees Revisions Proposed Rule

NACD Expresses Concerns with EPA TSCA Fees Revisions Proposed Rule

To Test or Not to Test: Tools, Rules, and Corporate Data in US Chemicals Regulation

When the Toxic Substances Control Act (TSCA) was passed by the US Congress in 1976, its advocates pointed to new generation of genotoxicity tests as a way to systematically screen chemicals for carcinogenicity. However, in the end, TSCA did not require any new testing of commercial chemicals, including these rapid laboratory screens. In addition, although the Environmental Protection Agency was to make public data about the health effects of industrial chemicals, companies routinely used the agency’s obligation to protect confidential business information to prevent such disclosures. This paper traces the contested history of TSCA and its provisions for testing, from the circulation of the first draft bill in the Nixon administration through the debates over its implementation, which stretched into the Reagan administration. The paucity of publicly available health and environmental data concerning chemicals, I argue, was a by-product of the law and its execution, leading to a situation of institutionalized ignorance, the underside of regulatory knowledge.

Distribution and Carcinogenicity of PCBs in Soil Contaminated with Transformer Oil in Selected Locations in Jos, Plateau State Nigeria

Soil from the vicinity of transformers installation in different locations in Jos, Plateau State was investigated for Polychlorinated Biphenyls (PCBs). The assessment was carried out for both total PCBs and congeners using Agilent 6975 GC-MS in ten different locations. The soil samples were extracted with 1:1 hexane- acetone in an ultrasonic bath, concentrated and cleaned with column chromatography using silica gel and hexane as eluting solvent. The result shows five locations were polluted with PCBs that exceed the maximum limit of 2.0mg/kg as permitted by the United States Toxic Substance Control Act (TSCA) with the following values NGS 1 (14.25), NGS 3 (4.47), NGS 6 (9.48), NGS 9 (8.21) and NGS 10 (5.05) while the others have NGS 2 (0.64), NGS 4 (1.85), NGS 5 (0.83), NGS 7 (0.95) in mg/kg respectively, NGS 8 value was below the instrument detection limit (0.0012mg/kg). The order for the total PCBs concentration in these selected locations are NGS 1 > NGS 6 > NGS 9 > NGS 10 > NGS 3 > NGS 4 > NGS 7 > NGS 5 > NGS 2. The carcinogenicity of the dioxin-like PCBs calculated as total toxicity equivalence concentration (TTEC) in these selected locations corresponds to NGS 1 (0.00001), NGS 2 (0.0000051), NGS 3 (0.0000054), NGS 4 (0.0000051), NGS 6 (0.0000063), NGS 7 (0.0000078), NGS 9 (0.0000051) and NGS 10 (0.0000051) respectively. The total cancer risk computed by addition of cancer risk due to ingestion, inhalation and dermal contact revealed that all the locations have very low to low cancer risk compared with the value recommended by the United State.

Enhanced Nontarget Screening Algorithm Reveals Highly Abundant Chlorinated Azo Dye Compounds in House Dust.

Humans spend 90% of their time indoors, but the majority of indoor pollutants remain unknown. In this study, a nontarget screening algorithm with reduced false discovery rates was developed to screen indoor pollutants using the Toxic Substances Control Act (TSCA) database. First, a putative lock mass algorithm was developed for post-acquisition calibration of Orbitrap mass spectra to sub-ppm mass accuracy. Then, a one-stop screening algorithm was developed by combining MS1 spectra, isotopic peaks, retention time prediction, and in silico MS2 spectra. A sufficient true positive rate (73%) and false discovery rate (5%) were achieved for the screening of halogenated compounds at a score cutoff of 0.28. Above this cutoff, 427 chemicals were detected from 24 house dust samples, including 39 chlorinated compounds. While some identified halogenated compounds (e.g., triclosan) are well known, 18 previously unrecognized chlorinated azo dyes were detected with high abundance as the largest class of chlorinated compounds. Two chlorinated azo dyes were confirmed with authentic standards, but the two most abundant chlorinated azo dyes were missed by the algorithm due to the limited breadth of the TSCA database. These compounds were annotated as chlorinated analogues of Disperse Blue 373 and Disperse Violet 93 using the DIPIC-Frag method. This study revealed the presence of highly abundant chlorinated azo dyes in house dusts, highlighting their potential health risks in the indoor environment.

Solvay withheld PFAS toxicity data, group claims

Environmental advocates are urging the US Environmental Protection Agency to fine Solvay Specialty Polymers a total of $434 million for allegedly withholding information about the toxicity of per- and polyfluoroalkyl substances (PFAS) the company used as processing aids to make fluoropolymers. At issue are chloroperfluoropolyether carboxylates, compounds that Solvay used as replacements for surfactants containing salts of perfluorononanoic acid (PFNA) or perfluorooctanoic acid (PFOA). Solvay stopped using those two chemicals more than a decade ago because they are toxic and persist in the environment. Both are known drinking-water contaminants. In a Jan. 26 petition , the advocacy organization Environmental Working Group (EWG) claims that Solvay violated reporting requirements under the Toxic Substances Control Act (TSCA) by waiting more than 5 years to notify the EPA about potential risks to human health and the environment posed by chloroperfluoropolyether carboxylates. According to the EWG, Solvay identified risks in a 4-week oral toxicity

EPA faces pressure to revamp chemical risk evaluations

This could be the year that the Environmental Protection Agency bolsters its evaluations of chemical risks under the Toxic Substances Control Act (TSCA). Congress gave the EPA sweeping new authorit...

Producing Ignorance Through Regulatory Structure: The Case of Per- and Polyfluoroalkyl Substances (PFAS)

This article examines how ignorance can be produced by regulatory systems. Using the case of contamination from per- and polyfluoroalkyl substances (PFAS), we identify patterns of institutionalized ignorance in U.S. chemical regulation. Drawing on in-depth interviews and archival research, we develop a chemical regulatory pathway approach to study knowledge and ignorance production through the regulatory framework, the Toxic Substances Control Act (TSCA). Investigating TSCA’s operation, we consider why PFAS were relatively recently recognized as a significant public health threat, despite evidence of their risks in the 1960s. The historical context of TSCA’s enactment, including the mobilization of the chemical industry, contributed to the institutionalization of organizational practices promoting distinct types of ignorance based on stakeholder position: chemical manufacturers who have discretion over knowledge production and dissemination, regulators who operate under selective ignorance, and communities and consumers who experience nescience, or total surprise.

Assessing risk of bias in human environmental epidemiology studies using three tools: different conclusions from different tools

BackgroundSystematic reviews are increasingly prevalent in environmental health due to their ability to synthesize evidence while reducing bias. Different systematic review methods have been developed by the US National Toxicology Program’s Office of Health Assessment and Translation (OHAT), the US Environmental Protection Agency’s (EPA) Integrated Risk Information System (IRIS), and by the US EPA under the Toxic Substances Control Act (TSCA), including the approach to assess risk of bias (ROB), one of the most vital steps which is used to evaluate internal validity of the studies. Our objective was to compare the performance of three tools (OHAT, IRIS, TSCA) in assessing ROB.MethodsWe selected a systematic review on polybrominated diphenyl ethers and intelligence quotient and/or attention deficit hyperactivity disorder because it had been endorsed by the National Academy of Sciences. Two reviewers followed verbatim instructions from the tools and independently applied each tool to assess ROB in 15 studies previously identified. We documented the time to apply each tool and the impact the ROB ratings for each tool had on the final rating of the quality of the overall body of evidence.ResultsThe time to complete the ROB assessments varied widely (mean = 20, 32, and 40 min per study for the OHAT, IRIS, and TSCA tools, respectively). All studies were rated overall “low” or “uninformative” using IRIS, due to “deficient” or “critically deficient” ratings in one or two domains. Similarly, all studies were rated “unacceptable” using the TSCA tool because of one “unacceptable” rating in a metric related to statistical power. Approximately half of the studies had “low” or “probably low ROB” ratings across all domains with the OHAT and Navigation Guide tools.ConclusionsTools that use overall ROB or study quality ratings, such as IRIS and TSCA, may reduce the available evidence to assess the harms of environmental exposures by erroneously excluding studies, which leads to inaccurate conclusions about the quality of the body of evidence. We recommend using ROB tools that circumvents these issues, such as OHAT and Navigation Guide.Systematic review registrationThis review has not been registered as it is not a systematic review.

Assessing Risk of Bias in Human Epidemiologic Studies Using Four Tools: Different Conclusions from Different Tools

Background: Systematic reviews (SR) are increasingly prevalent in environmental health due to their improved ability to synthesize large bodies of evidence, while minimizing bias. Different SR methods have been developed by the U.S. NTP’s Office of Health Assessment and Translation (OHAT), U.S. EPA’s Integrated Risk Information System (IRIS), and by the U.S. EPA under the Toxic Substances Control Act (TSCA), including how they assess risk of bias (ROB). The objective of this study was to compare the performance of three tools (OHAT, IRIS, TSCA) in assessing ROB, in epidemiology studies in order to identify best practices. Methods: Two reviewers independently applied the OHAT, IRIS and TSCA ROB tools to epidemiologic studies used in a previous SR on polybrominated diphenyl ethers and Intelligence Quotient and/or Attention Deficit Hyperactivity Disorder. This SR was chosen because it has been deemed good quality by the National Academy of Sciences. We measured the time to apply each tool and interrater reliability. Results: The time to complete the ROB assessments using the different tools varied widely (mean = 20, 32, and 40 minutes per study for the OHAT, IRIS, and TSCA tools, respectively). Interrater reliability was moderate for all tools (Kappa values= 0.56, 0.58, and 0.54, respectively). Based on the ROB assessments the overall quality of the body of evidence was similar for the OHAT and IRIS tools. All studies were rated ‘unacceptable’ using the TSCA tool because of an ‘unacceptable’ rating in only one metric not related to ROB, including ‘statistical power’ and ‘study design’. Therefore, no studies were retained to make a judgement about the quality of evidence. Conclusions: Using the TSCA tool may significantly reduce the available evidence to assess the harms of hazardous environmental exposures due to only one ‘unacceptable’ criterion. We recommend using the OHAT method when assessing ROB in SRs.

Risk of Bias Assessments in Evidence Review: Strengths and Limitations

Systematic review methods are increasingly the norm for evaluating evidence of environmental exposure and health effects to inform environmental health decisions as they support greater transparency in the scientific basis and judgements behind public health decisions. Systematic reviews have been adapted from clinical medicine (e.g. GRADE and Cochrane), where data comes largely from randomized, controlled trials. However, environmental health human studies typically rely on human observational studies due to ethical considerations. Thus, methods have been developed in environmental health to evaluate observational human studies that are adapted from Cochrane/GRADE to the environmental health context, and include the UCSF Navigation Guide systematic review method and the U.S. National Toxicology Program (NTP)’s Office of Health Assessment and Translation (OHAT) method. U.S. EPA has also developed methods for the Integrated Risk Information System (IRIS) and the U.S. EPA Toxic Substances Control Act (TSCA). The evaluation of the risk of bias (ROB) or internal validity of included human studies in a systematic review is a critical component in the method. ROB is a feature of a study’s methodological design, conduct, or analysis that may lead to a systematic bias in the true effect of the study. The ROB assessments conducted inform decisions on how the body of evidence will be analyzed. Several tools have been developed from the empirically based tools used to evaluate clinical interventions while accounting for observational human studies conducted in environmental health. This talk will compare strengths and limitations of different tools in assessing ROB tools used by UCSF Navigation Guide, NTP’s OHAT, U.S. EPA’s IRIS program, and by U.S. EPA under TSCA and how they compare to GRADE. Additionally, this talk will review best practices and those not recommended, including use of “overall quality scores”, via a case study relevant to human environmental epidemiology and discuss implications for systematic reviews in environmental health.

Recent Changes to the US Chemical Regulatory Process: Impacts on Public Health

The chemical regulatory process at the Environmental Protection Agency (EPA) has historically been vulnerable to pressure from chemical manufacturers and trade organizations. This pressure can be applied directly on the EPA’s review of and use of science on a specific chemical or can take the form of influence over the process by which science is used by the agency, including in the development of risk assessments, weight-of-evidence analyses, and hazard determinations or during the peer review process by EPA’s advisory committees. We evaluated the way in which process changes at the EPA made since 2017 have or likely will have impacts on the agency’s ability to use the best available science to inform policies that keep the public safe from chemical exposure. Examples include delays and suspension of work under the Integrated Risk Information System, restricting the advice that the Science Advisory Committee on Chemicals and the Science Advisory Board can provide to the agency, limiting the scope of assessment for chemicals under implementation of the Toxic Substances Control Act (TSCA), and issuing a TSCA systematic review framework that departs from scientific best practices. We found that these process alterations have resulted in insufficiently health-protective assessments and resulting policy decisions and fewer opportunities for members of the public to provide input. These impacts are felt especially for communities of color, low-income communities, and Indigenous communities who are experience an inequitable burden of chemical exposure. The speaker will lay out solutions that the EPA can put in place to address these challenges with the chemical regulatory process and prevent against undue influence from the regulated industry.