The Environmental Protection Agency (EPA) is proposing a new Risk Management Rule (released 5/3/23) to address the risk of injury to human health presented by methylene chloride based on research from the Toxic Substances Control Act (TSCA).
Brief Highlights: The New Rule,
- Would eliminate essentially all consumer use and significant industrial use
- Would eliminate almost half of current use
- Does not appear that research labs are affected much at this time, (would allow for reactants but most likely not cleaning
- Once approved there will be a 15-month implementation
- Preliminary requirements look a lot like the current OSHA standard 1910.1052
- Exposure limits would be much lower so that will be interesting to see how that would work from a regulatory standpoint
- To give an example, they are recommending 2 ppm for an 8-hr TWA exposure and 16 ppm for a STEL (Current OSHA limits are 25 ppm and 125 ppm respectively).
TSCA requires the EPA to address by rule any unreasonable risk or injury to health and apply requirements necessary to reduce or eliminate the risk.
In the new proposed EPA rule, methylene chloride, also known as dichloromethane, is described as acutely lethal, a neurotoxicant, a likely human carcinogen, and presenting additional non-cancer risks following chronic exposures.
The concern for an updated rule stemmed from the fact that methylene chloride is a central nervous system depressant with effects that can result in loss of consciousness and respiratory depression. There were 85 documented fatalities from 1980 to 2018, a majority of which were occupational fatalities.
Methylene chloride is widely used as a solvent in a variety of consumer and commercial applications including adhesives and sealants, automotive products, some lab processes, and paint and coating removers.
In 2019, EPA issued a final rule to prohibit the manufacture, processing, and distribution of methylene chloride in all paint and coating removers for consumer use based upon acute fatalities resulting from exposure. The EPA proposal under TSCA section 6(a) expands coverage and the main elements include:
(i) Prohibiting the manufacture, processing, and distribution of methylene chloride for all consumer
use,
(ii) Prohibiting most industrial and commercial use of methylene chloride,
(iii) Requiring a Workplace Chemical Protection Program (WCPP), including inhalation exposure c
concentration limits and related workplace exposure monitoring and exposure controls,
(iv) Requiring recordkeeping and downstream notification requirements for manufacturing,
processing, and distribution in commerce of methylene chloride,
(v) Providing a 10-year time-limited exemption under TSCA section 6(g) for civilian aviation from the
prohibition addressing the use of methylene chloride for paint and coating removal to avoid
significant disruptions to critical infrastructure; and
(vi) Providing a 10-year time-limited exemption under TSCA section 6(g) for emergency use of
methylene chloride in furtherance of National Aeronautics and Space Administration’s mission for
specific conditions which are critical or essential and for which no technically and economically
feasible safer alternative is available.
EPA stated the goal for the proposed regulation is to align with the current OSHA standard for methylene chloride, CFR 1910.1052, with additional requirements as necessary to address unreasonable risk. These additional requirements include: lower exposure limits, user notification, recordkeeping, periodic monitoring, and respirator selection criteria as part of the WCPP (Workplace Chemical Protection Program).
The proposal aligns with OSHA’s methylene chloride standard CFR 1910.1052; however, this rule differs from the OSHA regulation in the following ways:
- Exposure limits would be much lower; 2 ppm for an 8-hr TWA exposure and 16 ppm for a STEL exposure (current OSHA exposure limits are 25 ppm and 125 ppm respectively);
- Increased documentation and recordkeeping requirements;
- Increased employee involvement and notification;
- Increased periodic monitoring; and
- Specific respiratory selection requirements as part of the WCPP.
Workplace Chemical Protection Program (WCPP)
A WCPP includes inhalation exposure thresholds, monitoring, and recordkeeping requirements, as well as, other components, such as dermal protection.
EPA is proposing a WCPP for the following conditions of use: domestic manufacturing; import; processing as a reactant; processing for incorporation into a formulation, mixture, or reaction product; processing in repackaging; processing in recycling; industrial and commercial use as a laboratory chemical; industrial or commercial use for paint and coating removal from safety-critical, corrosion-sensitive components of aircraft and spacecraft by Federal agencies and their contractors; industrial or commercial use as a bonding agent for acrylic and polycarbonate in mission-critical military and space vehicle applications
Exposure Limits
The OSHA PEL for methylene chloride was adopted in 1971 and updated in 1997. The OSHA PEL was set at 25 ppm, based on the outcome of cancer and lack of documented feasibility data for potential PELs of less than 25 ppm.
EPA is proposing an Existing Chemical Exposure Limit (ECEL) under TSCA section 6(a) of 2 ppm (8 mg/m3 ) as an 8-hour TWA based on the chronic non-cancer human equivalent concentration for liver toxicity.
EPA is also proposing to establish an ECEL action level at half of the 8-hour ECEL, or 1 ppm (4 mg/m3 ) as an 8-hour time-weighted average. The ECEL action level would be a definitive cut-off point below which certain compliance activities, such as periodic monitoring, would not be required.
The ECEL is an 8-hour occupational inhalation exposure limit that represents the concentration at or below which an adult human, including a member of a potentially exposed or susceptible subpopulation, would be unlikely to suffer adverse effects if exposed for a working lifetime.
In addition to the 8-hour TWA ECEL, EPA is proposing a STEL of 16 ppm (57 mg/) as a 15-minute TWA. This short-term exposure limit is based on the non-cancer endpoint of central nervous system depression resulting from acute exposures.
The EPA STEL is based on decreased visual performance identified in an acute inhalation study on human subjects.
Please contact us for additional information such as List of Covered Industries, Monitoring Requirements, Protection Requirements, and Recordkeeping.