New Rules on Methylene Chloride: What Safety Professionals Need to Know

An effective solvent with serious risks

• By Martin Bermudez
• Sep 08, 2025

Methylene chloride (dichloromethane) is a powerful solvent in paint strippers, degreasers, and lab reagents. Its volatile nature and ability to dissolve many substances make it very useful, but inhaling high concentrations can cause immediate central nervous system depression (symptoms like dizziness, confusion, and loss of consciousness) and asphyxiation1. Over the long term, repeated exposure has been linked to organ damage and cancer. The U.S. Environmental Protection Agency (EPA) cited methylene chloride for its short-term neurotoxic effects and long-term risks of liver damage and cancer2. 

TSCA and New Regulations

In April 2024, the U.S. EPA used its authority under the Toxic Substances Control Act (TSCA) to regulate methylene chloride more stringently3. The new TSCA risk management rule is, in many ways, stricter than the U.S. Occupational Safety and Health Administration’s (OSHA) standard. The EPA’s rule slashes allowable exposure levels to a small fraction of OSHA’s limits: 

• It sets an inhalation exposure limit of 2 ppm (eight-hour TWA)—one-twelfth of OSHA’s PEL—and a short-term (15-minute) limit of 16 ppm, down from OSHA’s 125 ppm1,4,5.  

• It also establishes an “action level” of 1 ppm (a level at which employers must start taking protective measures) compared to OSHA’s 12.5 ppm5. 

The new rule also restricts how and where methylene chloride can be used. OSHA’s regulation only applies to workplace exposure, but TSCA gives EPA authority over the chemical’s distribution and use in commerce. The new rule bans methylene chloride in most consumer products and industrial/commercial uses.4 

EPA’s rule allows only a limited set of 13 specific uses for industrial and commercial settings to continue, under strict conditions4. These permitted uses include specific “critical” applications such as use as a chemical intermediate in manufacturing, use in laboratory research, use in some aerospace and defense-related processes (like aircraft component cleaning or solvent welding of parts), and a few others4. Unless your use of methylene chloride falls under an exempted category, it must be phased out. 

And the phase-out comes fast for the unexempted uses: most commercial uses must cease by April 28, 20264. A handful of specialized uses have a slightly longer tail. 

The Workplace Chemical Protection Program (WCPP)

The EPA’s rule also imposes a comprehensive Workplace Chemical Protection Program (WCPP) requirement on organizations permitted to continue using methylene chloride (those 13 conditions of use): 

• Initial exposure monitoring. Companies must start by assessing their current exposure levels. For most non-government employers, an initial air monitoring survey of methylene chloride exposure had to be completed by May 5, 20253. 

• New exposure limits and regulated areas. By August 1, 2025, all workplaces using methylene chloride were expected to comply with the EPA’s exposure limits (2 ppm TWA and 16 ppm STEL) and to have instituted mandatory dermal protections for any potential skin contact3.  

• Exposure control plan. A core element of the WCPP is a written Exposure Control Plan. By Oct. 30, 2025, private-sector employers using methylene chloride must prepare and implement this plan3. The plan must detail the whole hierarchy of controls used to eliminate or reduce methylene chloride exposure. 

• Ongoing monitoring. The rule mandates periodic re-monitoring of methylene chloride concentrations to ensure controls remain effective. If your initial monitoring showed levels well below the action level (under one ppm), you may only need to sample every five years5. But higher exposure readings trigger more frequent checks. 

Strengthened Protective Measures (Respirators, PPE & Training)

Even with good engineering controls, some tasks may still result in potential exposure to methylene chloride. The EPA’s rule builds stringent requirements for personal protective equipment (PPE) as a safety net, with more rigid specifications than existing OSHA rules: 

• Respiratory protection. Respirators are mandatory if an exposure could exceed the two ppm or 16 ppm limits after implementing all feasible engineering and administrative controls. Under the new rule, any required respiratory protection had to be in place by Aug. 1, 2025 3.  

• Dermal protection. Methylene chloride can also be absorbed through the skin, and it’s a skin irritant. The EPA now requires that chemically resistant gloves (and other appropriate dermal protection, such as aprons or sleeves, if needed) be provided to anyone handling methylene chloride3. Employers must select gloves impervious to methylene chloride 3. 

• Other PPE and hygiene measures. The rule effectively reinforces OSHA’s existing protective clothing and facilities requirements.3 

Compliance Timeline and Action Items for Employers

Workplace safety and health professionals should take prompt action to ensure compliance and, more importantly, protect workers. Below is a checklist of key steps and considerations: 

• Identify applicability. Under TSCA, the rule impacts anyone who manufactures, imports, processes, distributes, uses, or disposes of methylene chloride or mixtures containing it4. If you find any methylene chloride in your inventory, determine whether its use falls under one of the allowed categories or needs to be phased out. 

• Plan to discontinue banned uses. If you have any consumer-oriented products with methylene chloride, you should have stopped selling or distributing them—the cutoff was May 20254. For commercial/industrial uses that are not exempted, mark the April 28, 2026, deadline on your calendar4. That’s when most remaining uses must end. 

• Develop a Workplace Chemical Protection Program. If you qualify for continued use of methylene chloride, you must establish the required WCPP. This means, at minimum, conducting initial exposure monitoring (if you haven’t already) to quantify exposure levels3. 

• Implement engineering controls and ventilation. Meeting the 2-ppm limit likely requires improvements to ventilation or process enclosure in many cases. Evaluate your current controls against the new limits—what kept exposure below 25 ppm in the past may not get you below two ppm. Increase general ventilation in areas where methylene chloride is used, install local exhaust hoods or snorkels at the source of vapor release, or consider using closed systems3. 

• Upgrade PPE and training. Where ventilation and other controls still don’t reduce exposure enough, provide appropriate respirators and protective gear. Ensure your staff is medically evaluated, fit-tested for respirator use, and trained on properly using the equipment.  

• Conduct periodic and medical surveillance. Don’t treat exposure monitoring as a one-time compliance task. Schedule follow-up air monitoring per EPA’s requirements—at least every five years for low exposures, but more frequently (every three or six months) if your initial measurements were near or above the action level or limit.  

• Update safety data sheets and notifications. Manufacturers, importers, and distributors of methylene chloride or products containing it had specific deadlines in late 2024 to update their Safety Data Sheets to reflect the new rule. Even if you are a user and not a producer, you should obtain the latest SDS from your suppliers. 

The new TSCA rules provide a roadmap to significantly lower exposure limits, robust control requirements, and a mandate to verify that those controls work continuously. This is a prime opportunity for occupational health and safety professionals to champion process improvements, advocate for safer substitutes, and ensure that no one loses their life or health for a quick-stripping paint remover or a lab reagent. The regulations may be “the law,” but they align with the OH&S mission to send every worker home safe and healthy at the end of the day.  

REFERENCES:

1. https://tinyurl.com/3nk8ekv9 

2. https://tinyurl.com/w8p5j8p8 

3. https://tinyurl.com/4frutcct 

4. https://tinyurl.com/45dm77vc 

5. https://tinyurl.com/ye2xpn3d 

This article originally appeared in the September 2025 issue of Occupational Health & Safety.