EPA Releases Draft Revisions to Risk Determinations for PCE, NMP, Methylene Chloride, and TCE, Finding that Each, as a Whole Chemical Substance, Presents an Unreasonable Risk of Injury to Health

The U.S. Environmental Protection Agency (EPA) recently released draft revisions to the risk determinations for perchloroethylene (PCE) (87 Fed. Reg. 39085), N-methylpyrrolidone (NMP) (87 Fed. Reg. 39511), methylene chloride (87 Fed. Reg. 39824), and trichloroethylene (TCE) (87 Fed. Reg. 40520). Each draft revision to the risk determinations for these chemicals reflects EPA’s announced policy changes to ensure the public is protected from unreasonable risks from chemicals in a way that is supported by science and the law. In each draft revision, EPA finds that the chemical, as a whole chemical substance, presents an unreasonable risk of injury to health when evaluated under its conditions of use (COU).

For each chemical, the draft revised risk determination does not reflect an assumption that workers always and appropriately wear personal protective equipment (PPE). In each case, EPA states that this decision should not be viewed as an indication that EPA believes there is widespread non-compliance with applicable Occupational Safety and Health Administration (OSHA) standards. According to EPA, not assuming use of PPE in its baseline exposure scenarios reflects its recognition that certain subpopulations of workers exist that may be highly exposed because they are not covered by OSHA standards, their employers are out of compliance with OSHA standards, OSHA’s chemical-specific permissible exposure limits (PEL) (largely adopted in the 1970s) are “outdated and inadequate for ensuring protection of worker health,” or OSHA has not issued a PEL for that chemical.

Separately, EPA is conducting a screening approach to assess potential risks from the air and water pathways for several of the “first 10” chemicals, including PCE, NMP, methylene chloride, and TCE. In each case, the previous Administration excluded exposure pathways that were or could be regulated under another EPA-administered statute from the risk evaluations for these chemicals, resulting in certain air and water pathways not being fully assessed.

PCE

In its June 30, 2022, press release, EPA states that overall, 60 COUs out of 61 that EPA evaluated would drive the PCE whole chemical unreasonable risk determination. Removing the assumption that workers always and appropriately wear PPE in making the whole chemical risk determination for PCE would result in one COU in addition to the original 59 driving the unreasonable risk for PCE. Removing this assumption would also change many of the risks originally identified from the 59 COUs, including an additional route of exposure driving the unreasonable risk to workers, and additional risks for acute non-cancer effects and cancer from inhalation and dermal exposures.

EPA states that its screening approach will identify if there are risks that were unaccounted for in the risk evaluation for PCE. While this analysis is underway, EPA is not incorporating the screening-level approach into this draft revised unreasonable risk determination. If the results suggest there is additional risk, EPA will determine if the risk management approach being contemplated for PCE will protect against these risks or if the risk evaluation will need to be supplemented or revised formally.

Comments on the draft revised risk determination for PCE are due August 1, 2022.

NMP

EPA’s July 1, 2022, press release states that overall, 29 of the 37 COUs EPA evaluated would drive the NMP whole chemical unreasonable risk determination due to risks identified for human health. Removing the assumption that workers always and appropriately wear PPE in making the whole chemical risk determination for NMP would mean that three additional COUs in addition to the original 26 would drive the unreasonable risk determination for NMP. Additionally, for five COUs, acute effects in addition to chronic effects would now drive the unreasonable risk to workers. According to EPA, eight of the 37 COUs do not drive the unreasonable risk: consumer use of NMP in paint and coating removers; consumer use of NMP in adhesive removers; consumer use of NMP in paints and coatings in lacquer, stains, varnishes, primers, and floor finishes; consumer use of NMP in paint additives and coating additives not described by other codes in paints and arts and crafts paints; consumer use of NMP in other uses in automotive care products; consumer use of NMP in other uses in cleaning and furniture care products, including wood cleaners, gasket removers; and consumer use of NMP in other uses in lubricant and lubricant additives, including hydrophilic coatings; and distribution in commerce.

EPA states that during problem formulation, it conducted a first-tier screening analysis for the ambient air pathway to near-field populations downwind from industrial and commercial facilities releasing NMP that indicated low risk. In the final risk evaluation, EPA conducted a first-tier analysis to estimate NMP surface water concentrations and did not identify risks from incidental ingestion or dermal contact during swimming. This resulted in the ambient air and drinking water pathways for NMP not being fully assessed in the 2020 risk evaluation.

According to EPA, its screening approach will identify if there are risks that were unaccounted for in the risk evaluation for NMP. While this analysis is underway, EPA is not incorporating the screening-level approach into this draft revised unreasonable risk determination. If the results suggest there is additional risk, EPA will determine if the risk management approach being contemplated for NMP will protect against these risks or if the risk evaluation will need to be supplemented or revised formally.

Comments on the draft revision to the risk determination for NMP are due August 1, 2022.

Methylene Chloride

In its July 5, 2022, press release, EPA states that overall, 52 of the 53 COUs EPA evaluated would drive the methylene chloride whole chemical unreasonable risk determination due to risks identified for human health. Removing the assumption that workers always and appropriately wear PPE in making the whole chemical risk determination for methylene chloride would mean that five additional COUs in addition to the original 47 would drive the unreasonable risk determination for methylene chloride. Additional inhalation risks would drive the unreasonable risk in three COUs and additional risk to workers for acute and chronic non-cancer dermal exposures and for cancer from inhalation exposures would also drive the unreasonable risk in “many of those” 52 COUs. One out of 53 COUs would not drive the unreasonable risk: distribution in commerce.

EPA states that its screening approach will identify if there are risks that were unaccounted for in the risk evaluation for methylene chloride. While this analysis is underway, EPA is not incorporating the screening-level approach into this draft revised unreasonable risk determination. If the results suggest there is additional risk, EPA will determine if the risk management approach being contemplated for methylene chloride will protect against these risks or if the risk evaluation will need to be supplemented or revised formally.

Comments on the draft revision to the risk determination for methylene chloride are due August 4, 2022.

TCE

EPA states in its July 7, 2022, press release that overall, 52 COUs out of 54 that EPA evaluated would drive the TCE whole chemical unreasonable risk determination. Removing the assumption that workers always and appropriately wear PPE in making the whole chemical risk determination for TCE would not add additional COUs to the original 52 conditions that drive the unreasonable risk determination. According to EPA, removing this assumption would also add to many of the risks originally identified from the 52 COUs, including the identification of additional risks for acute non-cancer effects and cancer effects from inhalation and dermal exposures as driving the unreasonable risk within many of those COUs. Two out of 54 COUs do not drive the unreasonable risk: consumer use of TCE in pepper spray and distribution in commerce.

EPA states that its screening approach will identify if there are risks that were unaccounted for in the risk evaluation for TCE. While this analysis is underway, EPA is not incorporating the screening-level approach into this draft revised unreasonable risk determination. If the results suggest there is additional risk, EPA will determine if the risk management approach being contemplated for TCE will protect against these risks or if the risk evaluation will need to be supplemented or revised formally.

Comments on the draft revised risk determination for TCE are due August 8, 2022.

Commentary

Bergeson & Campbell, P.C. (B&C^®) applauds EPA’s work with advancing its intended revisions to the risk determinations on the “first 10” risk evaluations. We note, however, that EPA’s revisions, although claimed to be “supported by science and law,” appear to conflict with the U.S. National Academies of Sciences, Engineering, and Medicine’s (NASEM) evaluation of EPA’s systematic review method it used in the “first 10” risk evaluations, and with EPA’s own regulations promulgated for risk evaluations. We question EPA’s baseline assumption of the absence of PPE, as this seems counter to Congressional intent for the purpose of the TSCA amendments. Below, we provide context on each of these points.

Systematic Review

In the final PCE risk evaluation, EPA stated: “To meet these TSCA section 26 science standards [i.e., best available science and weight of scientific evidence], EPA used the TSCA systematic review process described in the Application of Systematic Review in TSCA Risk Evaluations document [hereinafter the “2018 SR Document”].” EPA included the same statement in the final risk evaluations for NMP, methylene chloride, and TCE. EPA further stated in the Federal Register notices for the draft revised unreasonable risk determinations for PCE, NMP, methylene chloride, and TCE that “EPA views the peer reviewed hazard and exposure assessments and associated risk characterization as robust and upholding the standards of best available science and weight of the scientific evidence per TSCA sections 26(h) and (i).” EPA did not, however, state in the Federal Register notices that NASEM reviewed its 2018 SR Document and concluded that “The OPPT approach to systematic review does not adequately meet the state-of-practice.” It is, therefore, unclear how EPA considers that its application of the 2018 SR Document, as used in the “first 10” risk evaluations, including PCE, NMP, methylene chloride, and TCE, satisfies the scientific standards of TSCA Section 26.

Risk Evaluation Regulation

On July 20, 2017, EPA promulgated its final rule for the “Procedures for Chemical Substance Risk Evaluations,” that was codified under 40 C.F.R. Subpart B. Under Section 702.47, the regulation states: “As part of the risk evaluation, EPA will determine whether the chemical substance presents an unreasonable risk of injury to health or the environment under each condition of uses [sic] within the scope of the risk evaluation, either in a single decision document or in multiple decision documents.” Though EPA claims that this language supports a whole chemical risk determination approach for PCE, NMP, methylene chloride, and TCE, we question this view. In our view, this Section unambiguously supports a COU-specific approach to risk determinations.

Personal Protective Equipment

EPA stated in the Federal Register notice for the draft revised unreasonable risk determination on PCE, NMP, methylene chloride, and TCE that “EPA proposes that the risk determination should be explicit that it does not rely on assumptions regarding the use of personal protective equipment (PPE) in making the unreasonable risk determination under TSCA section 6.” This decision appears to conflict with TSCA Section 26(k), which requires the EPA Administrator to “take into consideration information relating to a chemical substance or mixture, including hazard and exposure information, under the conditions of use, that is reasonably available to the Administrator.” For example, EPA acknowledged in the Federal Register notice for the draft revised unreasonable risk determination on PCE that “For the December 2020 PCE risk evaluation, EPA assumed based on reasonably available information that workers use PPE—specifically respirators with an APF ranging from 25 to 50 and gloves with PF 10 or 20—for 26 occupational conditions of use.” EPA justified its baseline assumption of no PPE, in part, on its identification of unreasonable risks for 25 of the 26 COUs where PPE was assumed. We note, however, that the presence or absence of risks does not negate the requirements of considering reasonably available information, particularly since this information may aid with understanding those risks.

It may be a question of semantics. Previously, EPA concluded during its risk evaluation that use with certain PPE is not an unreasonable risk so EPA issued an order that those COUs are not an unreasonable risk. EPA would then have to promulgate regulations requiring the use of such PPE during risk management. Under the current approach, EPA concludes during its risk evaluation that use with certain PPE is not an unreasonable risk, but the “whole chemical” is an unreasonable risk, so EPA must promulgate regulations requiring the use of such PPE during risk management. The outcome is the same, namely the issuance of regulations that require PPE for certain uses. The primary difference between these outcomes is when EPA takes final agency action. With the whole chemical approach, EPA delays final agency action until the promulgation of the risk management rule.

Conclusions

B&C encourages stakeholders to consider these issues in the context of each of EPA’s draft unreasonable risk determinations, given that these same issues will more than likely continue to be considered by EPA similarly in the “next 20” risk evaluations. EPA has given some insight on its position based on adverse comments to these issues. For example, in the final unreasonable risk determination on the cyclic aliphatic bromide cluster (HBCD), EPA justified its use of the 2018 HBCD SR Document as providing “sufficient” information “to make the unreasonable risk determination and inform risk management.” We note the distinction between “best available science” and “sufficient available science,” given that the former is a legal requirement, whereas the latter appears to be a pretext for not meeting the standard. It may be the case that EPA is relying upon the best available science, but the flaws in the 2018 SR Document preclude drawing that conclusion unless and until EPA conducts another systematic review under an updated, more robust, and coherent systematic review standard. This could be especially problematic if EPA proceeds with risk management rules based on “sufficient” data and later discovers that there is additional information that EPA should have incorporated into its risk evaluation, but did not. Therefore, we encourage stakeholders to provide public comments to EPA on these issues in recognition of the fact that silence will be tantamount to acceptance of EPA’s continued use of approaches that appear to fall short of meeting the scientific standards under TSCA Section 26.