Background                                                                      

Carbon tetrachloride (CTC) is a common solvent used in a variety of applications and is found in some academic research labs. The EPA determined that carbon tetrachloride 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 December 2024, which prohibits all commercial and most industrial uses. CTC was previously banned from consumer use in 1970.

While this rule does not ban the use and handling of CTC in research laboratories, it does place CTC on EPA’s regulatory list. An exemption for use as a laboratory chemical is granted, provided that a workplace chemical protection program (WCPP) is developed.

What are the Health Risks?

Carbon tetrachloride poses both non-cancerous and cancerous health risks from acute and chronic inhalation and dermal exposure. University staff exposure can increase the risk of cancer based on animal studies; cause liver, kidney, reproductive, developmental, and genetic toxicity; and cause irritation, sensitization, and temporary central nervous system depression.

New Exposure Limits

The new EPA regulation severely reduced the exposure threshold relative to the OSHA standard (See Table 1). To put this in perspective, the odor threshold for carbon tetrachloride is 10 parts per million (ppm), which is 333 times the new eight-hour time weighted average (TWA, 0.03ppm).

COMPLIANCE TIMELINE

EHRS Needs Your Help to Ensure Compliance with EPA and OSHA

1. If your lab or area has CTC that is no longer in use, please submit a Chemical Waste Pickup Request Form. Please remove the CTC from your chemical inventory to reflect its disposal.
2. If the lab or area is using CTC for applications prohibited by the TSCA final rule, this use is no longer allowed for these applications. Refer to this guide for examples of products containing CTC.
3. Please note that the use of CTC in facilities for purposes other than use as a laboratory chemical is prohibited unless the use is specifically exempted by the EPA Final Rule. Please submit a Chemical Waste Pickup Request Form. Please remove the CTC from the lab or area’s chemical inventory to reflect its disposal.
4. If your lab or area is interested in substituting another solvent for CTC, please refer to Table 3 and/or contact EHRS at ehrschem@temple.edu with any additional questions or concerns.

Please note that other chlorinated solvents such as 1,2-dichloroethane are under EPA review and are likely to be placed under similar restrictions. Therefore, they should not be considered as alternatives.

Workplace Chemical Protection Program (WCPP)

All research laboratories unable to eliminate carbon tetrachloride from their processes must develop a WCPP to limit employee exposure. EHRS staff will assist in WCPP implementation and provide resources where possible. The program will include:

• Exposure control plan: All users must identify and implement exposure controls to to a level at or below the 8-hour TWA (0.03ppm). This includes a description of the regulated area, restricted access to regulated areas, use of a chemical fume hood or glove box, direct dermal contact controls, and reporting procedure for any changes that may increase emplyee exposure.
• Initial monitoring: All employees or a single individual in an area representing the worst-case scenario will be monitored by EHRS for carbon tetrachloride exposure. Results indicating no exposure will be confirmed by remonitoring within 15 days.
• Establishment of a regulated area: Areas where airborne concentrations of carbon tetrachloride  will be marked as a designated area with restricted access.
• Respiratory Protection: Respiratory protection in accordance with air monitoring results will be required in areas when inhalation exposure exceeds acceptable limits.
• Engineeering Controls: The EPA has issued prescribed engineering controls. Any work being conducted with carbon tetrachloride must be performed in a chemical fume hood or glove box.
• Dermal Protection: Chemical resistant gloves such as polyvinyl alcohol or Viton are required to prevent exposure to hands. Impervious clothing covering is required for exposed areas of the body. A lab coat is required to protect clothing. Training for donning and doffing protective equipment is required at least annually.
• Training: Staff will undergo training prior to working in areas where carbon tetrachloride is used.
• Periodic Monitoring: Areas where carbon tetrachloride will be monitored periodically by EHRS staff for inhalation exposure depending on risk or if there are procedural changes. Exposure levels below exposure limits will be monitored every 5 years. All other concentrations will require monitoring every 3 or 6 months depending on severity.

Other Resources

• EPA Carbon Tetrachloride; Regulation under Section 6(a) of the Toxic Substances Control Act
• EPA Risk Evaluation of CTC
• EPA Unreasonable Risk Determination