Methylene Chloride Safety

Methylene Chloride (DCM) Compliance

Overview of the EPA Final Rule

In May 2024, the U.S. Environmental Protection Agency (EPA) finalized rule 40 CFR Part 751, Subpart B under the Toxic Substances Control Act (TSCA). This rule imposes requirements for continued use of methylene chloride (DCM) in laboratory (lab) and industrial settings.

All University of Arkansas laboratories using methylene chloride must comply with the EPA’s requirements.

Who Is Affected

Any researcher, faculty, staff, or student using methylene chloride at concentrations ≥0.1% must meet these requirements.

Workplace Chemical Protection Program (WCPP)

To comply with the EPA rule, each laboratory using DCM must implement a WCPP which includes:

A DCM specific Standard Operating Procedures (SOP), tailored to the lab’s use.
A defined designated use area, documented in the SOP.
Exposure monitoring conducted by ENHS, when required (e.g., baseline or follow-up sampling).
Dermal exposure controls, including multilaminate gloves (e.g., Silver Shield).

Important Note: Nitrile gloves alone are not sufficient and may only be used as an outer mechanical layer over chemical-resistant gloves.

Elimination or Substitution Consideration

Whenever feasible, eliminate or substitute methylene chloride with a safer alternative. See the bottom of this page for aternative solvents guidance.

If unable to eliminate or substitute, complete the following steps.

Required Steps Before Using Methylene Chloride

Complete the Lab Specific SOP
All labs must download, complete, and submit a lab-specific DCM SOP that describes the process, location, PPE, and emergency procedures for use.
Note: This SOP fulfills the PHS Request Form requirement, as DCM is classified as a Particularly Hazardous Substance (PHS).
Submit to ENHS for Review
Email the completed SOP to enhs@uark.edu. ENHS will review the SOP and submit it to the Hazardous Substance Committee (HSC) for approval.
Approved SOP
Once approved, the SOP and any associated documentation must be available in the lab.

Designated Use Area

DCM may only be used in areas that meet all the following criteria:

Clearly demarcated work area (e.g., with tape).
Restricted access during active use (only trained, authorized personnel).
Warning signage must be posted prior to use (download signage here).

The Principal Investigator is responsible for maintaining the designated area in a clean, controlled, and access-limited condition.

Spill Response and Emergency Procedures

If a spill occurs inside a fume hood:

Use lab spill kit (e.g., PIG pads).
Dispose of waste in a properly labeled hazardous waste container.
Report the spill to ENHS.

If a spill occurs outside a fume hood:

Evacuate the area.
Call ENHS (479-575-5448) or UAPD (479-575-2222).
Seek medical attention if exposure is suspected.

If skin or eye contact occurs:

Flush the affected area with water for 15 minutes.
Remove contaminated clothing.
Report the exposure and seek medical evaluation.

Waste Management

Label all containers: “Methylene Chloride - (include other constituents and percentages, (e.g., Dichloromethane 50%, Water 50%)).
Store hazardous waste in designated Satellite Accumulation Area (SAA).
If the waste container cannot be tightly sealed, it must be stored in a fume hood designated as a SAA.
When ready for disposal, complete a Hazardous Waste Pick Up Request form and email the completed form to enhs@uark.edu.

Training Requirements

All DCM users must:

Review and sign the lab-specific Methylene Chloride SOP.
Complete PPE training (e.g., proper use, limitations, disposal).
Complete any task-specific training from the PI.

Training must be repeated when:

The SOP is revised.
New personnel are added.
Engineering or administrative controls change.

Training records must be retained with the WCPP documentation.

Alternative Solvents to Methylene Chloride

This list is intended as a general reference and may not include all possible items. Before selecting an alternative solvent, please consult with the manufacturers of the chemical and equipment it will be used with to ensure compatibility.

Application

Suggested Alternatives

Reference(s)

Chromatography

Mixed with Heptanes

· 3:1 EtOAc:EtOH*

· EtOAc

· Isopropanol

Mixed with MTBE

· 3:1 EtOAc:EtOH*

· MeOH

Convenient Guide to Help Select Replacement Solvents for DCM