How can I continue to use methylene chloride?

All researchers unable to eliminate methylene chloride (DCM) from their processes must follow the Workplace Chemical Protection Program (WCPP), developed by Health, Safety, and Risk Management (HSRM), to limit employee exposure. HSRM staff will assist in WCPP implementation and provide resources where possible.

The WCPP program includes:

Expand all

Initial Monitoring

All employees or a representative individual for a worst case scenario in a specific area will be monitored for methylene chloride exposure no later than May 5, 2025, or within 30 days of initial use for new users.

Regulated Area

Areas exceeding methylene chloride exposure limits will be designated as a restricted access area and will be indicated by signage, floor tape, and flagging.

Exposure Control Plan

Implement controls to reduce airborne exposure below 2 ppm (8-hour TWA) or 16 ppm (15-minute STEL). Move equipment into fume hoods, cap flasks during transfer, install vented enclosures, etc.

Respiratory Protection

Use of Self Contained Breathing Apparatus (SCBA) or supplied air are required in areas where exposures exceed 2 ppm (8-hour TWA) or 16 ppm (15-minute STEL); cartridge respirators are prohibited.

Lab Gloves

Use chemical-resistant gloves (e.g. Laminate (SilverShield or AlphaTec 02-100), neoprene, or PVA) to prevent dermal exposure. Nitrile or latex gloves can be worn over laminate gloves for dexterity, but they do not provide protection and cannot be worn on their own.

Training

Staff must complete online training before working in a restricted area, including staff that do not plan to use methylene chloride.

HSRM is preparing an online training module that will be available on Training Hub starting July 2025. Training should be completed by Oct 30, 2025. Training should be repeated whenever procedures change or if periodic monitoring indicates increased exposure over time. Each lab will incorporate methylene chloride training into their annual lab specific training.

Periodic Monitoring

HSRM will periodically monitor restricted areas, with frequency based on exposure levels and procedural changes. Exposure levels below the action limit (1 ppm) for the 8-hour TWA and below the 15-minute STEL (16 ppm) will be monitored every 5 years. All concentrations over the indicated limits will require monitoring every 6 or 3 months depending on severity.

Waste Consolidation

We ask that laboratories who produce methylene chloride waste to separate methylene chloride containing solutions from other organic solvent waste and consolidate it into a dedicated methylene chloride waste container (i.e., 4-liter glass bottle, 20-liter carboy). Keeping methylene chloride containing waste separate from other organic solvent waste will help ensure the safety of HSRM’s Regulated Waste team, assist in maintaining EPA compliance, and keep the University’s disposal costs down.

Implementation Timeline

Nov 9, 2026 — Initial monitoring complete. You will not be able to use methylene chloride in your lab after this date if
you have not enrolled in the monitoring program or HSRM has cleared your lab based on use.
Feb 8, 2027 — Environmental controls in place. All work or small equipment (rotovaps, automated chromatography, etc.) must be moved to a fume hood, or enhanced environmental controls are in place for tasks that cannot be relocated (vented enclosures, snorkels, enhanced PPE, supplied air, etc.).
May 10, 2027 — Implement exposure control plan. A written program (developed by HSRM) documenting environmental controls, regulated areas, review plans, and procedures for reevaluating tasks when changes are made that increase the risk of methylene chloride exposure is made available. Information in this document will be used to write task-specific SOPs and/or lab-specific exposure control plans.

Why is this required?

The EPA determined that methylene chloride poses an
unreasonable risk to human health or the environment ” following review under Toxic Substance Control Act (TSCA) regulations. The final rule was published in April 2024, which prohibits most consumer and commercial uses. An exemption for laboratory use is granted, provided that a workplace chemical protection program (WCPP) is developed.

What are the health risks?

Methylene chloride poses both non-cancer and cancer health risks from acute and chronic inhalation and dermal expo-sures. University staff exposed to DCM have an increased risk of developing cancer (based on some animal studies), neuro-toxicity effects (headaches, dizziness, etc.), heart and liver damage, and skin or eye irritation.

Questions?

If you have any questions regarding the use of Methylene Chloride (DCM) or the implementation of the Workplace Chemical Protection Program (WCCP), please contact your HSRM Safety Partner or Health, Safety, and Risk Management at [email protected] or (612) 626-6002.