On January 24, 2020, the U.S. Environmental Protection Agency (EPA) released the draft risk evaluation of carbon tetrachloride, “a solvent primarily used in the manufacturing of chlorinated compounds and petrochemicals.” Carbon tetrachloride is the seventh of the first ten chemicals to undergo risk evaluation under the amended Toxic Substances Control Act (TSCA). EPA published a Federal Register notice on January 27, 2020, announcing the availability of the draft risk evaluation and beginning a 60-day comment period. 85 Fed. Reg. 4658. The TSCA Science Advisory Committee on Chemicals (SACC) will hold a preparatory virtual meeting on February 4, 2020, to consider the scope and clarity of the draft charge questions for the peer review. On February 25-26, 2020, SACC will hold an in-person public meeting to consider and review the draft risk evaluation. EPA will provide comments submitted on the draft risk evaluation on or before February 19, 2020, to SACC for their consideration before the meeting. Comments received after February 19, 2020, and prior to the oral public comment period during the meeting will be available to the SACC for their consideration during the meeting. Comments on the draft risk evaluation are due March 27, 2020.

Draft Risk Evaluation Findings

EPA states that it “reviewed 15 potential uses, all of which are associated with industrial and commercial work and are primarily associated with the manufacturing process of other chemicals.” According to EPA, there are no consumer uses of carbon tetrachloride. EPA made the following initial determinations on risk:

• EPA did not find risk to the environment or workers. For all the conditions of use included in the draft risk evaluation, EPA states that it has preliminarily found no unreasonable risks to the environment under any of the conditions of use or to workers when appropriate personal protective equipment is used; and

• EPA’s draft risk evaluation preliminarily found unreasonable risks associated with chronic inhalation exposure for occupational non-users (ONU). EPA found that ONUs -- those workers in the vicinity of carbon tetrachloride’s use but not directly working with the chemical -- could be adversely affected by carbon tetrachloride under certain conditions of use.

EPA states that these initial determinations “are based on a draft risk evaluation of the reasonably available information and are not EPA’s final determinations on whether this chemical presents unreasonable risks under the conditions of use.” EPA will use feedback received from the public comment and peer review processes to inform the final risk determinations.

EPA notes that the draft risk evaluation and the initial risk determinations for carbon tetrachloride are not a final action. The draft risk evaluation represents EPA’s preliminary conclusions, findings, and determinations on carbon tetrachloride and will be peer reviewed by SACC. The draft risk evaluation includes input from other EPA offices, as well as other federal agencies.

Using Products Safely and Alternatives

EPA states that for any chemical product, it “strongly recommends that users carefully follow all instructions on the product’s label and on the safety data sheets” (SDS). According to EPA, workers using carbon tetrachloride products should continue to follow the label/SDSs and applicable workplace regulations and “should properly use appropriate personal protective equipment, as needed.” EPA notes that SDSs developed by the manufacturer remind users to only use the product in well-ventilated areas.

Commentary

EPA’s assessment of carbon tetrachloride is interesting for several reasons. As a result of its evaluation of conditions of use, EPA eliminated some uses, notably use as a solvent or processing aid for the manufacture of pharmaceuticals, because EPA found no evidence that those conditions of use are ongoing. It is worth noting that one particular example was the fact that carbon tetrachloride is no longer used during the manufacture of ibuprofen because of a synthetic process commercialized in the mid-1990s that earned BASF and Hoechst-Celanese a Presidential Green Chemistry Challenge Award. EPA also found that use as a degreaser in the aerospace industry is no longer ongoing. EPA’s response to these past uses will be particularly interesting. EPA could seek to prohibit future use as a degreaser in the aerospace industry either using a Section 5(a)(2) Significant New Use Rule (SNUR) or in a final Section 6 action. On the other hand, EPA’s attempt to limit its use as a processing aid or solvent in the manufacture of a pharmaceutical seems to be excluded from TSCA authority. EPA might instead use Section 9(a) and refer its concerns to the Food and Drug Administration for its consideration.

Also notably, EPA’s risk evaluation only found potential unreasonable risk for some ONUs for both cancer and non-cancer end points.  It remains to be seen if EPA’s use of personal breathing zone (PBZ) monitoring data is a good surrogate for ONU exposures.  EPA specifically requests that the SACC review EPA’s use of PBZ data in this way.

EPA is to be commended for completing another draft risk evaluation. It is now the responsibility of the stakeholder community to provide EPA feedback on its assessment, both what EPA has done well and what EPA can do to improve its analysis.