The US Environmental Protection Agency’s latest chemical risk assessment finds little concern with the use of carbon tetrachloride, as long as workers wear personal protective equipment. The agency, however, did find inhalation risks associated with exposures to unprotected workers who do not handle the chemical directly but work in facilities where it is used.
Carbon tetrachloride is one of the first 10 chemicals the EPA is evaluating under the 2016 revisions to the Toxic Substances Control Act. The agency has released seven of the draft assessments so far. All 10 assessments must be finalized by June.
Carbon tetrachloride is used in the manufacturing of refrigerants, including hydrochlorofluorocarbons, hydrofluorocarbons, and hydrofluoroolefins, as well as in processing agricultural products, chlorinated chemicals, and some solvents. The EPA classifies carbon tetrachloride as “likely to be carcinogenic to humans.” The chemical also affects the central nervous system, liver, and kidneys, and it is a skin irritant. In addition, it is one of the substances known to deplete Earth’s stratospheric ozone layer.
As the EPA has for other recently assessed chemicals, the agency ignores the risks of carbon tetrachloride to the general population through mechanisms such as environmental emissions from industrial operations. The agency punted the evaluation of those risks to other programs that address air, water, biosolids, and disposal.
The Consumer Product Safety Commission banned carbon tetrachloride in consumer products in the US in 1970. The EPA did not evaluate the risks of carbon tetrachloride in any consumer uses, stating that “it is highly unlikely that there are any ongoing uses of carbon tetrachloride that could be considered legacy uses.”
The EPA also did not consider ozone depletion risks in its assessment of carbon tetrachloride, claiming that most nonfeedstock uses of the chemical were phased out in 1996 under the Clean Air Act and the Montreal Protocol. The Montreal Protocol is an international treaty that aims to protect the ozone layer. The treaty, however, does not regulate feedstock uses.
The EPA’s chemicals advisory committee plans to review the carbon tetrachloride draft assessment during a Feb. 25–26 meeting. The agency is accepting comments from the public until March 27.