The Environmental Protection Agency (EPA) published two significant final rules in December relating to Trichloroethylene (TCE) and Perchloroethylene (PCE), aka “Perc.” The two solvents are widely used, so those in charge of environmental compliance will want to pay attention to the implementation timelines.  Both actions were taken under the Toxic Substance Control Act (TSCA).

The two volatile chemicals are frequent drivers in environmental remediation.  They are widely used in a number of industrial and commercial practices and are often at the center of environmental litigation.  It is not uncommon for multiple sites to be potential sources of TCE in groundwater requiring forensic analysis to identify responsible parties.  PCE, used in dry cleaning, is also a common groundwater contaminant.  Both TCE and PCE are volatile organic compounds and potential sources of vapor intrusion.

Are the Rules at Risk of Being Overturned?

Are these final rules vulnerable to being overturned by the Trump Administration?  According to Beverage and Diamond, “Both rules have effective dates prior to Inauguration Day, January 20, 2025.  That means they will not be subject to the anticipated 60-day regulatory freeze and potential pull-back by the incoming Trump administration.  They are, however, potentially subject to invalidation under the Congressional Review Act.  In the absence of such action, judicial review of both rules is likely.”

Trichloroethylene (TCE) Rule

The final rule that will effectively ban the use of TCE over a phase-in period was published on December 17, 2024.

In the final rule, the EPA states, “TCE is an immunotoxicant and developmental toxicant and is carcinogenic to humans by all routes of exposure.  This final rule is specifically intended to address the unreasonable risk of injury to health that EPA has identified in the 2020 Risk Evaluation for TCE…”

Implementation Timeline

While the TCE ban is gradual, it is a complete ban – consumer, industrial, and commercial.  The bans will take place ranging from one year from the rule becoming final to 50 years after the rule is final.

The law firm, Beverage and Diamond provided the following with respect to the timeline of the phase out of TCE.

March 17, 2025:

All manufacturing (including importing and manufacturing for export), except as specified elsewhere.

June 16, 2025:

All processing (including processing for export) and distribution of TCE including TCE-containing products, except as specified elsewhere.

All manufacturing of TCE for industrial and commercial use for batch vapor degreasing in open-top and closed-loop degreasing equipment, except as specified elsewhere.

September 15, 2025:

All industrial and commercial use of TCE, except as specified elsewhere; all processing of TCE for industrial and commercial use for batch vapor degreasing in open-top and closed-loop degreasing equipment, except as specified elsewhere.

All disposal of TCE to industrial pre-treatment, industrial treatment, or publicly-owned treatment works, except as specified elsewhere.

December 18, 2025:

All industrial and commercial use of TCE for batch vapor degreasing in degreasing in open-top and closed-loop degreasing equipment, except as specified elsewhere.

June 10, 2026:

All manufacturing of TCE for processing of TCE as a reactant/intermediate, except as specified elsewhere.

All manufacture of TCE for processing of TCE for industrial and commercial use as a processing aid for listed applications, except as specified elsewhere.

December 18, 2026:

All processing of TCE as a reactant/intermediate, except as specified elsewhere.

All industrial and commercial use of TCE as a processing aid for the listed applications, except as specified elsewhere.

December 18, 2029:

All industrial and commercial use of TCE as a processing aid for lithium battery separator manufacturing and the manufacturing (including importing), processing, and distribution in commerce of TCE.

June 18, 2033:

All industrial and commercial use of TCE as an intermediate for manufacturing HFC–134a and manufacturing (including importing), processing, and distribution in commerce for that use.

Some specialized uses of TCE extend to the year 2074.

The regulatory threshold is 0.1%, so products containing TCE at concentrations less than 0.1% by weight are not subject to the prohibitions and restrictions of this final rule.

Also, see the Federal Register notice section “What action is the Agency taking?

This final rule is effective on January 16, 2025.

Dry Cleaners Store Front

Use of PCE in dry cleaning, where it is often referred to as Perc, will be phased out over 10 years (Photo by Jeremy Perkins on Unsplash).

Perchloroethylene (PCE/PERC) Rule

The final rule that limits the use of PCE for all but a  few uses was published on December 18, 2024.

The EPA states, “PCE presents an unreasonable risk of injury to health, without consideration of costs or other nonrisk factors, including an unreasonable risk to potentially exposed or susceptible subpopulations (PESS) identified as relevant to the 2020 Risk Evaluation for PCE by EPA, under the conditions of use…”

The PCE rule differs from the TCE rule in a few ways.  The final rule for PCE will phase out all consumer uses and many industrial uses within three years.  Use of PCE in dry cleaning, where it is often referred to as Perc, will be phased out over 10 years (Source: Chemical Engineering and News).

Implementation Timeline

The following timeline is from the Beveridge and Diamond blog.

September 9, 2026:

All processing of PCE, including PCE-containing products, for consumer use.

All processing of PCE for industrial and commercial use of PCE, except as specified elsewhere.

December 8, 2026:

All distribution of PCE, including PCE-containing products, to retailers for any use other than dry cleaning.

March 8, 2027:

All distribution by retailers of PCE, including PCE-containing products.

All distribution of PCE, including PCE-containing products, for consumer use and industrial and commercial uses other than as specified elsewhere.

June 7, 2027:

All industrial and commercial use of PCE, including PCE-containing products, except as specified elsewhere.

As stated in the final rule, the EPA “Recognizes that some conditions of use may be important for national security applications or for other critical needs.  For example, PCE is a critical diluent (to modify the consistency or other properties in a formulation) for maskant applied to military and commercial aircraft skin panels that prevents chemical milling or industrial etching of certain areas.  It is also used in petrochemical manufacturing as a processing aid in catalyst regeneration for reformate and isomerate (these are gasoline blending stocks) that make up an estimated 45% of the United States gasoline pool.  Therefore, this final rule allows certain continued uses of PCE provided that sufficient worker protections are in place to address the unreasonable risk for certain occupational conditions of use.”

The EPA is finalizing a de minimis threshold of 0.1%, which the EPA is referring to in this final rule as a regulatory threshold so that products containing PCE at concentrations less than 0.1% by weight are not subject to the prohibitions of this final rule.

Also see “What action is the Agency taking?”

This final rule is effective on January 17, 2025.

The use of TCE and PCE has been significantly reduced over the past few decades, in part due to their toxicity and in part to the problems created when there is a release.

As stated previously, this and other environmental rules passed under the Biden Administration may be overturned or challenged under the Trump Administration.

Environmental Advice

Dragun Corporation has assisted the regulated community with environmental compliance, assessment/remediation, and litigation support since 1988.  If you need assistance with an environmental issue, including litigation support, contact Jeffrey Bolin, M.S., CHMM, at 248-932-0228, Ext. 125.

Dragun Corporation does not use artificial intelligence to write our blogs or other material.

Alan Hahn drafted this blog.  Alan has an undergraduate degree in Environmental Studies and completed a graduate program in Environmental Management.  He has worked in environmental management for more than 45 years.  He has written hundreds of blogs and articles.  His published work includes Michigan Lawyers Weekly, Detroiter, Michigan Forward, GreenStone Partners, Manure Manager Magazine, Progressive Dairy, and HazMat Magazine.

Jeffrey Bolin, M.S., reviewed this blog.  Jeff is a partner and senior scientist at Dragun Corporation.  He is a published author, frequent speaker, and expert witness.  His expertise in environmental due diligence, PFAS, vapor intrusion, and site assessments has led to projects in the US, Canada, and overseas.  See Jeff’s Bio

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