TSCA's Next Chapter: EPA Finalizes 1,2-Dichloroethane Risk Evaluation — What Chemical Manufacturers Must Do Now

On May 5, 2026, the Environmental Protection Agency finalized its risk evaluation for 1,2-dichloroethane (EDC)—the solvent, intermediate, and chemical linchpin of the vinyl chloride industry. The determination is straightforward and consequential: 1,2-dichloroethane presents unreasonable risk of injury to human health driven by worker exposure across 15 conditions of use. No consumer or general-population risk. No environmental prohibition (in the final document).

What this means: the clock is now running on TSCA Section 6(a) rulemaking. Within one year—by May 2027—the EPA must propose risk management actions. Within two years, a final rule. And for every manufacturer who uses, processes, or handles 1,2-dichloroethane, the window for preparation is now.

This is the playbook you’ve already seen with trichloroethylene (TCE) and methylene chloride. But the timeline is accelerated, and the worker-exposure evidence is strong. Here’s what you need to do today.

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The Risk Evaluation: What EPA Found

1,2-dichloroethane (CASRN 107-06-2)—also called ethylene dichloride or EDC—is a colorless, volatile liquid that smells like chloroform and has a single dominant industrial use: it is heated and cracked to produce vinyl chloride monomer (VCM). Over 90% of all EDC produced in the U.S. is converted directly to VCM; the rest is used in adhesives, degreasing compounds, paints, and as a laboratory reagent.

EPA was mandated to evaluate EDC because it was one of the TSCA “first 10” priority chemicals designated in 2019. The agency published a draft risk evaluation in November 2025; industry and the public commented. Today’s final determination reflects those comments, peer review, and EPA’s weight-of-evidence analysis.

What EPA Concluded:

• Unreasonable Risk: Yes. Based on inhalation and dermal exposure, plus inhalation exposure to occupational non-users (ONUs—e.g., maintenance workers, supervisors, fork-lift operators who don’t directly handle EDC but work in contaminated areas).
• Risk Driver: Worker Exposure. All 15 conditions of use with unreasonable-risk determinations are workplace-exposure scenarios. Consumer use, general-population ambient exposure, and environmental ambient exposure were not identified as sources of unreasonable risk.
• Health Effects: Cancer and Systemic Toxicity. 1,2-dichloroethane has been shown to cause kidney and other cancers; non-cancer effects include renal, nasal, immune system, and reproductive harm.
• Conditions of Use Affected: Manufacturing, repackaging, recycling, use in adhesives/sealants/lubricants, laboratory use, and disposal.

EPA’s determination is focused. It is not banning the chemical. It is not declaring a consumer emergency. It is saying: worker-exposure controls are inadequate under current practice, and EPA will now design a regulatory pathway to fix that.

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The Exposure Baseline: OSHA vs. NIOSH — A 50x Gap

Here is where the regulatory tension becomes clear.

The OSHA Permissible Exposure Limit (PEL) for 1,2-dichloroethane is 50 ppm (parts per million) as an eight-hour time-weighted average (TWA). This standard was established in 1989 and is based on older toxicological data. If your facility keeps airborne EDC below 50 ppm during a worker’s shift, you are OSHA-compliant.

The NIOSH Recommended Exposure Limit (REL) for 1,2-dichloroethane is 1 ppm (TWA) and 2 ppm (short-term exposure limit, STEL). NIOSH classifies 1,2-dichloroethane as a potential occupational carcinogen. The 1 ppm recommendation reflects modern carcinogenic-potency data and NIOSH’s mission to protect workers to the fullest extent feasible.

That is a 50-fold difference.

Current OSHA compliance does not equal safety under NIOSH’s standard. And here is the implication: EPA’s proposed risk management rule—following the playbook of TCE and methylene chloride—may impose an exposure limit significantly lower than the current OSHA PEL, potentially much closer to the NIOSH REL.

What does that mean operationally? If your facility today operates at, say, 30 ppm (well below OSHA’s 50 ppm), and EPA’s proposed rule sets a limit of 5 ppm or 2 ppm, you will need to upgrade engineering controls—ventilation systems, enclosed processes, respiratory protection programs—or fundamentally change your operation.

Manufacturers who have not conducted baseline exposure assessments in the past two years should start now.

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The Vinyl Chloride Industry: Ground Zero

1,2-dichloroethane is an intermediate, not a finished product. The largest affected sector is vinyl chloride and PVC manufacturing.

U.S. VCM/EDC Production Footprint:

The U.S. is the world’s largest vinyl chloride producer, driven by low-cost chlorine and ethylene feedstocks and integrated production. As of 2019, the U.S. produced approximately 8.8 million metric tons of VCM annually—mostly in the Gulf Coast region (Louisiana, Texas). Key producers include Westlake Corporation (the largest), Olin Corporation, AGC Chemicals, and Kaneka Corporation.

For these companies, 1,2-dichloroethane is not a fringe exposure—it is a core operational footprint. Thermal cracking of EDC to produce VCM is the standard industrial route. Workers involved in EDC manufacturing, storage, transfer, equipment maintenance, and inspection are routinely exposed.

Secondary Affected Sectors:

• Adhesive and sealant formulators
• Paint and coatings manufacturers
• Metal plating and degreasing shops
• Ethylene glycol producers (EDC use in synthesis routes)
• Laboratory chemical suppliers
• Waste treatment and incineration facilities

For these sectors, EDC is a component or process chemical, not the primary product. The risk evaluation is still relevant—if your workers handle EDC in any quantity, the upcoming rule may affect you.

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Conditions of Use: Which COUs Will Get Hit in the Proposed Rule?

EPA identified 15 conditions of use with unreasonable worker-exposure risk. The proposed rule will not necessarily restrict all 15 equally. Some may be banned outright; others may face tightened exposure limits or mandatory engineering controls.

Here is what the 15 COUs likely include (exact list subject to final EPA documentation):

1. Manufacturing of 1,2-dichloroethane — Highest-exposure COU; likely to face stringent controls or use narrowing
2. Repackaging/recycling/processing operations — Secondary manufacture; exposure control feasible
3. Use in adhesives/sealants/lubricants/greases — Solvent role; substitution may be feasible
4. Use in cleaning and degreasing compounds — Solvent role; substitution may be feasible
5. Industrial use in synthetic intermediate production (other than VCM)
6. Commercial laboratory chemical use — Small-volume; low-exposure risk but easy to substitute
7. Disposal and waste treatment — Fugitive emissions; controls feasible

Strategic Question for Manufacturers: Which of the 15 COUs applies to your operation? If it is COUs 1–2 (manufacturing/processing), you face high compliance burden. If it is COUs 3–7 (downstream use, laboratory), you may have alternative chemical pathways.

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The Regulatory Timeline: What’s Coming and When

TSCA Section 6(a) imposes statutory deadlines:

• Proposed Rule: Within one year of final evaluation publication = by May 5, 2027
• Final Rule: Within two years of final evaluation publication = by May 5, 2028
• Phase-In Compliance: Varies by COU; typically 6–36 months from final rule publication

Expected Proposed Rule Timeline:

Based on EPA’s track record with TCE and methylene chloride, here is the realistic schedule:

Phase	Timing	EPA Activity	Your Window
Proposed Rule Publication	April–May 2027	Federal Register notice; regulatory text and preamble released	Preliminary impact assessment
Public Comment Period	60–90 days (June–August 2027, est.)	Industry, labor, environmental groups submit written comments; may include technical data, cost analyses, feasibility studies	Critical window: Submit evidence-based technical comments if your operation would be significantly impacted
Comment Analysis & Revision	June–December 2027	EPA reviews comments; revises proposed rule language; conducts cost-benefit updates	Monitor docket; prepare for potential changes
Final Rule Publication	January–May 2028	Federal Register final rule; compliance deadlines specified by COU	Confirm your operation’s phase-in start date
Compliance Phase-In Begins	Mid-2028 through 2031	Phase-in periods begin (e.g., 6 months for COU 1; 18 months for COU 5; 36 months for COU 7)	Execute capital projects, engineering upgrades, operational changes

Key Takeaway: The proposed rule will provide the roadmap. If you think the proposed rule is wrong—infeasible, economically disproportionate, or technically misaligned with real-world operations—the 60–90 day comment period is your only leverage to influence the final rule.

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What the Proposed Rule Might Look Like (Based on TCE and Methylene Chloride Precedent)

EPA has now finalized Section 6(a) risk management rules for two chemicals in the “first 10” list. Here is what the agency typically includes:

1. Use Prohibitions or Use Narrowing

For high-exposure COUs (manufacturing, repackaging, certain industrial uses), EPA may:

• Outright ban the use
• Narrow the use to closed-loop systems only
• Require certification that alternatives are not feasible

Example from TCE (Trichloroethylene): EPA prohibited TCE in aerosol degreasing and in vapor degreasing in new equipment, but allowed it in some closed-loop industrial systems with engineering controls. Manufacturers using TCE in spray or batch degreasing had to switch.

2. Exposure Limits Below OSHA PEL

EPA may set a regulatory exposure limit (REL) that is lower than OSHA’s 50 ppm. This could be:

• 5 ppm
• 2 ppm
• 1 ppm (aligned with NIOSH)

This would require:

• Upgrade of local exhaust ventilation (LEV) systems
• Process enclosure or substitution of closed-loop operations
• Enhanced respiratory protection (fit-testing, maintenance, training)
• Personal air monitoring to demonstrate compliance

3. Engineering Control Requirements

Specific mandates such as:

• Enclosed processes (not open vats or spray operations)
• Local exhaust ventilation with 90–95% capture efficiency
• HEPA or carbon filtration on all emissions
• Process water treatment for aqueous wash streams containing EDC

4. Personal Protective Equipment (PPE)

• Respiratory protection program (fit-testing, cartridge replacement schedules, training)
• Dermal protection (gloves, protective clothing, work uniforms)
• Hygiene facilities (shower, change rooms, separate street-clothes storage)

5. Work Practice Controls

• Restricted-access areas for EDC-handling operations
• Segregation of EDC-exposed workers from general workforce during high-exposure tasks
• Decontamination protocols (change rooms, shoe covers, hand hygiene)
• Training on hazards, controls, and proper use of PPE

6. Labeling and Notification

• Updated SDS (Safety Data Sheet) language reflecting carcinogenic hazard
• Workplace hazard warning signs
• Employee notification procedures (who is exposed; what controls are in place; where to report concerns)

7. Exposure Monitoring and Recordkeeping

• Baseline exposure assessment (air sampling) within 6 months of compliance date
• Ongoing exposure monitoring (annual or after process changes)
• Recordkeeping for 30+ years (occupational health records)
• Reporting to OSHA and/or EPA (if required)

8. Phase-In Deadlines

EPA will specify different compliance dates for different COUs based on feasibility and the availability of alternatives. For example:

• Use Prohibitions: 6–12 months (e.g., new equipment must use alternatives)
• Process Modification/Upgrading: 18–24 months (time to design, procure, install new ventilation)
• Full Compliance with Engineering Controls: 24–36 months (largest capital-intensive projects)

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What Manufacturers Must Do — A Phased Preparation Roadmap

Phase 1: June 2026 – April 2027 (Pre-Proposed Rule)

Objective: Establish baseline, assess impact, prepare for public comment.

Actions:

1. Conduct Baseline Exposure Assessment

   • Air sampling at your facility: measure current 1,2-dichloroethane concentrations in worker-breathing zones
   • Include all exposure scenarios: manufacturing, maintenance, inspection, emergency response
   • Compare results to OSHA PEL (50 ppm), NIOSH REL (1 ppm)
   • Identify exposure hotspots (high-exposure work tasks, equipment, areas)

2. Inventory Conditions of Use

   • Which of the 15 EPA-identified COUs apply to your operation?
   • Quantify volume, frequency, duration of EDC exposure by COU
   • Document current engineering controls (ventilation, enclosure, PPE)
   • Assess adequacy of current controls relative to NIOSH REL

3. Evaluate Alternatives and Technical Feasibility

   • Are there alternative solvents or chemicals that can replace EDC in your process?
   • What is the cost, availability, and performance of alternatives?
   • If process modification is needed, what is the timeline and capital requirement?
   • For VCM manufacturers: does your EDC thermal cracking process have technical constraints that limit alternative feedstocks?

4. Estimate Compliance Costs

   • Engineering control upgrades (ventilation, enclosure, process redesign)
   • Alternative chemical procurement and testing
   • Respiratory protection program expansion (fit-testing, equipment, training)
   • Capital equipment and installation
   • Timeline for completion and operational downtime

5. Benchmark Against Industry

   • What are competitors and peer manufacturers doing?
   • Are industry trade associations (ACC, SPI, chemical producers) preparing joint comments?
   • What data or insights are available from published case studies (e.g., TCE compliance cost analyses)?

Phase 2: May–August 2027 (Proposed Rule + Public Comment Period)

Objective: Influence the proposed rule by submitting credible, evidence-based comments.

Actions:

1. Analyze the Proposed Rule

   • Read the Federal Register preamble: what is EPA’s rationale for the proposed limits, use restrictions, and compliance deadlines?
   • Identify language or requirements that are technically infeasible, economically disproportionate, or inconsistent with peer data

2. Prepare Technical Comments

   • If the proposed exposure limit is infeasible (e.g., your exposure baseline shows 12 ppm even with best-available controls), submit data showing the technical barriers
   • If alternatives do not exist or are unsafe, document that and propose interim solutions
   • If the compliance timeline is too aggressive, propose a more realistic phase-in based on capital project lead times
   • Submit peer-reviewed literature, case studies, or engineering reports that support your position

3. Participate in Industry Coalition Comments (if applicable)

   • Many chemical manufacturers participate in trade-association comments (through ACC, SPI, or industry-specific groups)
   • Coalitions carry more weight with EPA; individual company comments are noted but less influential
   • Consider whether joining an industry comment effort aligns with your competitive interests

4. Estimate Impact on Business Operations

   • Quantify the cost and timeline for your compliance path (use prohibition, process modification, alternative chemical adoption, etc.)
   • If compliance creates significant economic hardship or market dislocation, note that in your comment
   • Propose alternative compliance pathways if the proposed rule seems unnecessarily restrictive

Phase 3: 2028–2029 (Final Rule Through Compliance Ramp-Up)

Objective: Execute compliance projects within the phase-in timeline.

Actions:

1. Capital Planning and Procurement

   • If engineering control upgrades are required (ventilation, enclosure), begin design and vendor selection
   • Lead times for custom ventilation systems: 3–6 months design, 2–4 months fabrication, 1–2 months installation
   • Plan procurement to avoid supply-chain delays

2. Alternative Chemical Testing and Validation

   • If switching to an alternative solvent or intermediate, conduct bench-scale and pilot-scale testing to confirm performance
   • Ensure the alternative is approved for your application (adhesive, degreasing compound, laboratory use, etc.)
   • Update supplier agreements, procurement, and inventory management

3. Respiratory Protection Program Updates

   • Expand fit-testing capacity if new workers will be in respiratory-protection status
   • Purchase additional respirators and cartridges
   • Update training programs for PPE selection and use

4. Operational Procedure Updates

   • Revise standard operating procedures (SOPs) to reflect new exposure limits, engineering controls, and work practices
   • Update facility layouts and restricted-access areas
   • Brief workforce on regulatory changes and what compliance means operationally

5. Exposure Monitoring and Recordkeeping System

   • Establish air-sampling protocol (frequency, location, methodology) to demonstrate ongoing compliance
   • Create data management system for exposure records (OSHA 300 logs, air-sampling results, fit-testing records)
   • Designate compliance coordinator and periodic audit schedule

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Why This Matters: The Methylene Chloride and TCE Playbooks

EPA has done this twice in the past five years. Both times, the agency finalized a risk management rule that dramatically altered how manufacturers could use these chemicals. Understanding what happened with those rules helps manufacturers anticipate what is coming with EDC.

Methylene Chloride (2020–2022)

Timeline:

• Risk Evaluation Finalized: December 2019
• Proposed Rule: December 2020 (13 months later)
• Final Rule: November 2022 (35 months later)

Key Restrictions:

• Paint/coating stripper use banned for consumers and professional applications
• Occupational use (furniture refinishing, semiconductor manufacturing) permitted under stringent controls: exposure limit set at 50 ppm (same as OSHA PEL, but with mandatory engineering controls and respiratory protection)
• Spray application prohibited; open-batch application prohibited
• Businesses using methylene chloride had 18–36 months to comply depending on the use

Outcome:

• Many paint-stripper manufacturers switched to alternative solvents or NMP (n-methylpyrrolidone)
• Furniture refinishers either installed closed-system ventilation or stopped using methylene chloride
• Industry adjusted; compliance was expensive but feasible

Trichloroethylene (2020–2025 and ongoing)

Timeline:

• Risk Evaluation Finalized: February 2020
• Proposed Rule: September 2021 (19 months later)
• Final Rule: Published January 2023, with multiple compliance-date extensions due to legal challenges and feasibility concerns
• Compliance Phase-Ins: 2024–2027 (ongoing)

Key Restrictions:

• Vapor degreasing in new equipment: banned
• Vapor degreasing in existing equipment: permitted through 2026 (with compliance extensions pending)
• Aerosol degreasing: phased out by 2024
• Closed-loop batch degreasing: permitted under exposure limits (25 ppm, then 50 ppm at point of use)

Outcome:

• Metal-finishing shops either converted to aqueous or non-chlorinated alternatives, or upgraded to EPA-approved closed-loop systems (capital cost $500K–$2M+ per facility)
• Some manufacturers fought EPA in court and won temporary delays
• Full compliance extended beyond original deadlines due to alternative-availability issues
• Semiconductor and aerospace manufacturers (high-purity degreasing needs) struggled most; some continue to seek exemptions

Lessons for 1,2-Dichloroethane Manufacturers

1. EPA Will Be Firm on Worker Protection. Both methylene chloride and TCE rules prioritized worker-exposure reduction above all else. Cost and feasibility arguments were secondary. Expect the same for EDC.

2. Substitution Is the Path Forward (for some COUs). In both cases, manufacturers who had viable alternatives switched. Those without alternatives fought harder and got longer phase-ins. For EDC adhesive/degreasing uses, alternatives exist (NMP, green solvents). For VCM manufacturing, EDC is the intermediate—no easy substitute (short of process redesign).

3. Comment Period Matters. Manufacturers who submitted detailed cost-benefit analyses and technical feasibility comments in the proposed-rule phase influenced EPA’s final decision on compliance timelines. Those who waited until the rule was final had no leverage.

4. Legal Challenges Delay Enforcement. Both methylene chloride and TCE rules faced legal challenges from industry, labor, and environmental groups. Delays of 6–24 months are common. Manufacturers should budget for uncertainty in compliance timelines.

5. Compliance Is Achievable But Expensive. In both cases, manufacturers ultimately complied. The cost ranged from low (reformulation, alternative chemical adoption) to high (process redesign, capital equipment). None of the rules created market collapse—but they did reshape competitive dynamics and supply chains.

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The Content Angles for Your Organization

For Vinyl Chloride and PVC Manufacturers

Your EDC exposure is operational and large-volume. The proposed rule will likely tighten exposure limits or narrow use pathways for manufacturing and processing. Action items:

• Baseline exposure assessment: Do you know your current EDC concentrations at your facility?
• Engineering control audit: Can your current ventilation system achieve 5 ppm? 2 ppm? 1 ppm?
• Alternative assessment: If EDC manufacturing/processing faces use narrowing, are there alternative VCM synthesis routes (e.g., direct chlorination of ethylene)? Cost and feasibility?
• Supply-chain risk: If competitors face the same constraints, will EDC supply tighten or price spike?

For Adhesive, Paint, and Solvent Manufacturers

EDC is a solvent component, not a raw material you can eliminate overnight. But substitutes exist (NMP, DMF, green solvents). Action items:

• Formulation review: What % of your products contain EDC? Can those formulations be reformulated with alternatives?
• Customer impact: Will your customers (furniture, appliance, automotive manufacturers) accept alternative-solvent formulations? Any performance differences?
• Cost modeling: What is the incremental cost of alternative solvents, and how will you absorb or pass it on?
• Regulatory timeline: If EDC use in adhesives/paints is prohibited or severely restricted by 2029, when do you need to transition your supply chain?

For Metal Plating and Degreasing Shops

EDC-based degreasing compounds are standard. But aqueous and non-chlorinated alternatives are available. Action items:

• Equipment compatibility: Can your current degreasing equipment (tanks, spray systems) work with alternative solvents? Any modifications needed?
• Part cleanliness: Does the alternative solvent achieve the same cleanliness standard for metal parts?
• Waste management: Are waste streams (spent solvent, sludge) easier or harder to dispose of with alternatives? Cost differential?
• Cost and supply: Is the alternative more expensive? Is it readily available from suppliers?

For Laboratory Chemical Suppliers

EDC is used as a reagent and laboratory solvent in small quantities. Substitution is usually straightforward. Action items:

• Inventory transition: How much EDC is in current stock? Can you transition customers to alternatives with minimal service disruption?
• Supplier relationships: Do your suppliers stock alternatives? Are delivery and pricing competitive?
• Customer communication: Many labs are not tracking EDC regulatory status; use this as an opportunity to proactively offer alternatives before the rule is final.

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The Next 12 Months: Your Preparation Window

From May 5, 2026 to May 5, 2027, you have a narrow window to establish your compliance baseline and prepare for the proposed rule. Manufacturers who conduct exposure assessments, evaluate alternatives, estimate costs, and prepare comments during this period will have maximum leverage when the proposed rule drops.

Those who wait until the proposed rule is published will be reactive. They will have only 60–90 days to understand the impact and submit comments. They will have less technical data and fewer cost-benefit arguments to influence the final rule.

Start now:

1. Call an industrial hygiene firm to conduct baseline air sampling at your facility.
2. Review the draft risk evaluation (published November 2025) and the final risk evaluation (published May 5, 2026) on EPA.gov.
3. Evaluate whether EDC can be substituted in your process, and quantify the cost and timeline.
4. If EDC is essential to your operation, begin upgrading ventilation and engineering controls now so you do not face a compliance crunch in 2028.
5. Join industry-coalition discussions (via trade associations or industry groups) if you want to submit joint comments during the proposed-rule period.

The TSCA Section 6(a) rulemaking for 1,2-dichloroethane is now in motion. The EPA clock is running. The time to prepare is now.

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Primary Sources

• 1,2-Dichloroethane; Final Risk Evaluation Under the Toxic Substances Control Act (TSCA); Notice of Availability — Federal Register, May 5, 2026
• Risk Evaluation for 1,2-Dichloroethane — EPA.gov
• ETHYLENE DICHLORIDE (1,2-DICHLOROETHANE) — OSHA Chemical Data
• CDC - NIOSH Pocket Guide to Chemical Hazards - Ethylene Dichloride — NIOSH/CDC
• What to Expect Under TSCA in 2026 — BD Law
• Draft Risk Evaluation Now Available for 1,2-Dichloroethane — AIHA

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About iSi Environmental

iSi Environmental provides TSCA compliance support, industrial hygiene assessment, exposure monitoring, and regulatory strategy services to chemical manufacturers, vinyl chloride producers, adhesive and paint formulators, and metal finishing shops across the Midwest and beyond. Whether you need baseline air sampling to establish your compliance position, alternative-chemical evaluation for your EDC-containing products, or expert comment preparation for EPA rulemaking, our team can help.

Contact iSi Environmental for a confidential compliance consultation.