In an expected action, on January 11, 2017, the Administrator of the U.S. Environmental Protection Agency (EPA) signed a proposed rule under Section 6(a) of the Toxic Substances Control Act (TSCA) to regulate the use of trichloroethylene (TCE) in vapor degreasing.  The proposed rule has not yet been published in the Federal Register, but a pre-publication version of the proposed rule is available on EPA’s website, along with a fact sheet and other information.  The proposed rule would prohibit the manufacture (including import), processing, and distribution in commerce of TCE, prohibit commercial use of TCE in vapor degreasing, require manufacturers, processors, and distributors, except for retailers of TCE for any use, to provide downstream notification of these prohibitions throughout the supply chain, and require limited recordkeeping.  Comments will be due 60 days after publication in the Federal Register.

Overview of Proposed Rule

The proposed rule is related to the proposed TSCA Section 6(a) rule on TCE aerosol degreasing and spot cleaning in dry cleaning facilities that was published in the Federal Register on December 16, 2016.  81 Fed. Reg. 91592.  The two proposals together address risks for workers and consumers associated with exposure to TCE through inhalation that were identified in EPA’s 2014 TCE risk assessment.  EPA has stated that it intends to finalize both actions together.

Based on EPA’s analysis of worker exposures to TCE in its completed risk assessment (published before the date of enactment of the Frank R. Lautenberg Chemical Safety for the 21st Century Act), EPA believes that the use of TCE in vapor degreasing presents an unreasonable risk to human health.  More specifically, EPA believes that this use results in significant non-cancer risks under both acute and chronic exposures and significant cancer risks from chronic exposures.  EPA is not proposing to regulate other ongoing uses of TCE.  EPA states, however, that it has not concluded that other uses not included in the TCE risk assessment present low risks.

Under new TSCA Section 6(a), if EPA determines that a chemical presents an unreasonable risk of injury to health or the environment, without consideration of costs or other non-risk factors, including an unreasonable risk to a potentially exposed or susceptible subpopulation identified as relevant to the Agency’s risk evaluation, under the conditions of use, EPA must by rule apply one or more requirements to the extent necessary so that the chemical substance no longer presents such risk.

EPA states that it analyzed a wide range of options under TSCA section 6(a) in selecting the regulatory approach proposed in the rule.  EPA considered whether any one or a combination of options would address the identified unreasonable risks.  In so doing, EPA initially analyzed whether the regulatory options could reduce risks (non-cancer and cancer) to levels below those of concern based on EPA’s technical analysis of exposure scenarios.  For the non-cancer risks, EPA stated it would find an option to be potentially protective against the risk if it could achieve the benchmark margin of exposure (MOE) in its risk assessment for the most sensitive non-cancer endpoint.  EPA’s assessments also indicated that when such exposures meet the benchmark MOE for the most sensitive non-cancer endpoint, they also result in low risk for cancer.  After this technical analysis, EPA goes on to state that it considered how reliably a series of regulatory options would actually reach these most sensitive benchmarks and whether the option could be realistically implemented, or whether there were practical limitations concerning how well the option would mitigate the risks.

The proposed rule also considered the TSCA Section 6(c)(2) cost/benefit elements including the adverse effects and magnitude of exposure to TCE, its benefits for various uses, and the reasonably ascertainable economic consequences of the rule.  The proposed rule is identified as economically significant.  Further, because the proposed action would substantially prevent a specific condition of use, EPA was also required to consider, to the extent practicable, whether technically and economically feasible alternatives that benefit health or the environment will be reasonably available as a substitute when the proposed prohibition or other restriction takes effect.  EPA states that it identified a wide variety of technically and economically feasible alternatives for vapor degreasing with TCE, that it considered the potential risks associated with such alternatives, and that it found several to present relatively lower risks than those for TCE.  EPA is specifically requesting comments on TCE alternatives to help inform its further consideration.

The proposed rule also discusses implications under TSCA Section 9 concerning actions that could be taken under other federal laws as well as what will be required of EPA regarding scientific standards and the use of scientific information and methods in a manner consistent with the best available science that appear in Section 26(h) of new TSCA.

Commentary

The two proposed Section 6(a) rules on TCE are important as the first examples of EPA’s attempt to use its new TSCA Section 6(a) authority to regulate existing chemicals.  The proposed rules should be read carefully by interested stakeholders to gain an understanding of EPA’s thinking and approach to using its new, strengthened regulatory authority.

Our 2017 Predictions memo stated that the prospects were more positive for proceeding with the first TCE rule proposed in December, while there was significant potential for this second TCE rule (vapor degreasing use) to be withdrawn or re-proposed.  While we appreciate EPA’s care in drafting the current proposed rule, the rule is lengthy and complex with many important supporting documents in the docket that need careful review, and we do not see a clear basis for changing our forecast for this rule.  Part of the reason for this view is a point that we also made in our 2017 Predictions memo concerning EPA’s decision to conduct a risk evaluation focused on the other uses of TCE.  We continue to believe that this decision could have ripple effects in that any reopening of such a controversial risk assessment is likely to lead to issues concerning risks from TCE that will bleed through and affect at least the vapor degreasing proposed rule.

These points concerning the complexity of the rule, its record, and the implications of reopening the previously completed risk assessments also hold true for the recently proposed Section 6(a) rule on the use of methylene chloride and N-methyl pyrollidone (NMP) in paint strippers.  The methylene chloride/NMP proposed rule has not been published in the Federal Register as yet, but the pre-publication version is available on EPA’s website.