On April 27, 2020, the U.S. Environmental Protection Agency (EPA) released the draft risk evaluation of perchloroethylene. According to EPA, it reviewed 68 conditions of use and preliminarily found unreasonable risk to workers, occupational non-users (ONUs), consumers, bystanders, and the environment from certain uses. EPA will use feedback received from the peer review and public comment process to inform the final risk evaluation. EPA notes that if its final risk evaluation finds there are unreasonable risks associated with perchloroethylene under the specific conditions of use, EPA will propose actions to address those risks within the timeframe required by the Toxic Substances Control Act (TSCA). EPA’s actions could include proposed regulations to prohibit or limit the manufacture, processing, distribution in the marketplace, use, or disposal of perchloroethylene, as applicable. EPA will publish a notice in the Federal Register, beginning a 60-day comment period. EPA will also hold a virtual peer review meeting of the Science Advisory Committee on Chemicals (SACC) on the draft risk evaluation on May 26-29, 2020. The virtual peer review meeting will be open to the public to attend and provide comments.
Draft Risk Evaluation Findings
EPA reviewed industrial, commercial, and consumer uses of perchloroethylene and made preliminary findings on whether using perchloroethylene can cause unreasonable risks to human health or the environment. Among the uses reviewed by EPA are processing as a reactant/intermediate; processing aid in petroleum production; use as a dry cleaning solvent; use in vapor degreasing and cold cleaning; use in textile processing; use in photographic film; and incorporation into products including, but not limited to spot cleaners, adhesives, and brake cleaners. EPA notes that the risks found in the draft risk evaluation, including those associated with perchloroethylene’s use in dry cleaning, are preliminary and do not require any action at this time. EPA states that the risks it found may change based on comments received from the public and peer reviewers.
EPA’s draft risk evaluation preliminarily found unreasonable risk to workers, ONUs, consumers, bystanders, and the environment from a wide variety of uses. The primary health risk identified in the draft risk evaluation is neurological effects from short- and long-term exposure to perchloroethylene. For occupational scenarios, acute and chronic risks were found for multiple endpoints for all conditions of use, except for use of laboratory chemicals, under high-end inhalation or dermal exposure scenarios if personal protective equipment (PPE) was not used. EPA found that perchloroethylene presented unreasonable risks to workers for all conditions of use except for distribution in commerce, the industrial use of lubricants and greases (e.g., penetrating lubricants, cutting tool coolants), the industrial use of laboratory chemicals, the commercial use of lubricants and greases (e.g., penetrating lubricants, cutting tool coolants), and the commercial use of laboratory chemicals.
ONUs are expected to have lower exposure levels than workers in most instances but exposures could not always be quantified based on the available data and, in EPA’s view, risk estimates may be similar to workers in some settings. For consumer users and bystanders, risks identified for acute exposures were indicated for some but not all conditions of use. For consumers, medium- and high-intensity acute inhalation and dermal exposure scenarios indicated risk. According to EPA, the risk to consumers from perchloroethylene’s use in dry cleaning is from skin exposure to items cleaned with perchloroethylene. Use as a dry cleaning solvent presented risks for bystanders in the dermal scenario. EPA found unreasonable risks to ONUs from several of these conditions of use and to consumers from most of the relevant conditions of use. Deferring to the protections afforded by other EPA-administered statutes, EPA did not evaluate hazards, exposures, or risks to the general population.
EPA also found environmental risks to aquatic organisms from several conditions of use, including processing as a reactant/intermediate, recycling, use as a processing aid in petroleum production, and disposal. EPA found unreasonable risks to the environment from several of these conditions of use.
As noted above, conditions of use for which EPA preliminarily determined there to be no unreasonable risk include distribution in commerce and a few specific industrial, commercial, and consumer uses. EPA states that “[i]t is important to remember that these initial determinations are not EPA’s final determinations on whether this chemical presents unreasonable risks under the conditions of use.”
Using Products Safely
EPA states that while the risks found in the draft risk evaluation, including those for dry cleaning uses, do not require any action at this time, the information below provides ways to reduce exposure. For any chemical product, EPA “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 perchloroethylene products should continue to follow the label/SDSs and applicable workplace regulations and should properly use appropriate PPE, as needed. Additionally, EPA notes that SDSs developed by the manufacturer provide instructions on the proper use of perchloroethylene, including using the product in well-ventilated areas.
EPA suggests that consumers wishing to avoid exposure should ask retailers if products used contain perchloroethylene and consider not using products that contain perchloroethylene. EPA states that consumers also can choose not to use products where they do not know the active ingredients. EPA acknowledges that the risks from dry cleaning found in the draft risk evaluation “may be concerning.” To the extent that consumers want to avoid exposure to perchloroethylene, “they can ask which chemicals are used to clean their clothes and make the choice that’s right for them based on this information.” EPA states that it “is important to note that use of perchloroethylene in dry cleaning has decreased over time as companies shift to alternative chemicals and new technologies.”
Commentary
As is the case for many of the other “first ten” high-priority chemicals, EPA has identified numerous conditions of use in which there may be an unreasonable risk to workers and ONUs, especially in the high-end scenarios. It remains to be seen if an in-depth review of the point of departure (POD) and exposure scenarios stand up to scientific review.
Not surprisingly, there are many cases in which EPA identifies risk if workers are not using appropriate PPE. EPA also identifies some conditions of use that lead to unreasonable risk for workers using PPE. In numerous use scenarios, EPA found unreasonable risk via dermal exposure in the high-end exposure group, even when using gloves with a protection factor of 20. These risks might be mitigated with gloves that have a higher protection factor. In a smaller set of use scenarios, EPA found unreasonable risk via inhalation, even when using full-face respirators with an assigned protection factor (APF) of 50. In some cases where significant inhalation exposure is expected, such as aerosol use or vapor degreasing, EPA found unreasonable risk in the central tendency group, even with PPE (gloves and respirators). In these cases, exposures potentially could be controlled with better engineering controls to prevent worker and ONU exposures, an area that falls into the jurisdiction of the Occupational Safety and Health Administration (OSHA), as well as EPA under TSCA.
Perhaps the most problematic use scenarios are the consumer uses that EPA estimates present an unreasonable risk to both users and bystanders, even in the low-intensity user group. In some consumer use scenarios, exposure by inhalation or dermal routes in the moderate-intensity group is over 10-fold above EPA’s POD. In the high-intensity user groups, exceedances are on the order of 1,000-fold. Given the breadth of the consumer use scenarios in which EPA estimates unreasonable risk, EPA might have to seek a ban on most consumer uses.