OVERVIEW OF PERCHLOROETHYLENE (PERC)


EUROPEAN UNION

In October 2014, the European Chemical Agency (ECHA), the main authority body for the REACH-Regulation, published a Substance Evaluation Report which concluded that with all available hazardous data received on perchloroethylene (PERC), there is no need for additional regulatory actions like a re-classification, restriction or authorization of PERC. 

With its current Classification under the CLP-Regulation (Regulation with regards to Chemical Classification, Labelling and Packaging - Regulation (EC) No. 1272/2008)), PERC does not meet the criteria for a classification of Substance of Very High Concern (SVHC) under the REACH-Regulation.

Nevertheless, it needs to be mentioned that on April 20th 2023, the delegated CLP-Regulation officially entered into force. One of the main changes concerns the new hazard classes PMT and vPvM (Persistent, Mobile and Toxic and very Persistent & very Mobile), which are to be used in the future to classify substances that do not accumulate in the environment but are so mobile in soils that they could enter drinking water. Additionally, it is likely that these two new hazard classes will become criteria for the identification of SVHC under REACH.

In the future, PMT and vPvM will be used to classify substances that are either persistent, mobile and toxic or very persistent and very mobile. While for many substances there are no available data yet on mobility, this is not the case for PERC. Based on existing data, statements can already be made today as to whether PERC falls under these new hazard classes.

According to the definitions in the delegated CLP-Regulation, PERC fulfils the criteria for persistent and mobile, but not for toxic. PERC is not classified as carcinogenic category 1A or 1B.

PERC is therefore not expected to be classified as a PMT substance based on current data and classification criteria.

According to the definitions in the delegated CLP-Regulation, PERC meets the definition of vP but not vM.

PERC is therefore not expected to be classified as a vPvM substance based on current data and classification criteria.

In Europe, PERC remains a viable and effective option for metal cleaning.

 


UNITED STATES

Several solvents which are used in industrial parts cleaning operations, including prior and after heat treatment processes, are currently filed under Risk Evaluation by the Environmental Protection Agency (EPA).

The Risk Evaluation Process is part of the Toxic Substances Control Act (TSCA) and a list of chemicals under the Act is available in the public domain.

The Risk Evaluation Process is the second step, following Prioritization and before Risk Management, under TSCA. The purpose is “to determine whether a chemical substance presents an unreasonable risk to health or the environment, under the conditions of use, including an unreasonable risk to a relevant potentially exposed or susceptible subpopulation. As part of this process, EPA must evaluate both hazard and exposure, exclude consideration of costs or other non-risk factors, use scientific information and approaches in a manner that is consistent with the requirements in TSCA for the best available science, and ensure decisions are based on the weight-of-scientific-evidence”. [27]

The TSCA gives the EPA the authority to require reporting, record-keeping and testing requirements, and restrictions relating to chemical substances and/or mixtures. The Toxic Release Inventory (TRI) Program obligates companies, depending on the cleaning agent and the amount used in the cleaning processes, to report annually how much of each chemical is released to the environment (i.e. emitted to air or water, or placed in some type of land disposal) and/or managed through recycling, energy recovery and treatment.

There are various other regulations which affect industrial cleaning applications, such as The Clean Air Act including NESHAP, The Resource Conservation and Recovery Act or The Clean Water Act. The scope of this article is limited to TSCA only as this is a regulation which is applied all over the US without further break-down of state individual adoptions. However, SAFECHEM recommends readers to also take into account state specific regulation. There are very strict regulations in certain states like California which are further limiting the use of certain chemistries (e.g. on Ground Water Protection).

EPA announced on June 30th 2021 that they would further enlarge the scope of the risk assessment within TSCA by “developing a screening-level approach to conduct ambient air and surface water fenceline assessments” and by reviewing the use of personal protective equipment.

Experts expect that the maximum exposure level being associated with unreasonable risks are likely to be lower, perhaps much lower than those published by groups such as OSHA, the American Industrial Hygiene Association (AIHA) or the America Conference of Governmental Industrial Hygienists (ACGIH).

Currently all kind of brominated and chlorinated solvents are under review. This includes the use of perchloroethylene (PERC), methylene chloride (dichloromethane – DCM), trichloroethylene (TRIC) and 1-bromopropane (nPB) but also trans-dichloroethylene (t-DCE).

The EPA released a final revised evaluation on PERC in December 2022 and found unreasonable risks to workers, occupational non-users, consumers, and bystanders in 60 out of 61 conditions of use.

EPA will develop ways to address the unreasonable risks identified and take public comments on any risk management actions. Proposals by the EPA for PERC were already published in the Federal Register in June 2023. It proposed the continuous use of PERC under a Workplace Chemical Protection Program (WCPP) in vapor degreasing. Cornerstone of the WCPP is the proposed Existing Chemical Exposure Limit (ECEL) of 0.14 ppm as an 8-hour average exposure limit. If companies can adhere to this value and implement a reasonable WCPP including regular exposure measurements, they can continue to use PERC. The public was given time to comment on the proposal until August 15th 2023. Currently, EPA is reviewing all received comments and will take them into consideration for their final rule on PERC under TSCA, expected to be published in 2024.

 


CHINA

China has filed a notice in relation to the so-called Blue Sky Plan in 2019, which aims to improve air quality in several big cities in China. This notice was the starting point for several legislative actions regulating and restricting air quality-affecting topics.

Under this plan a new Chinese standard was published in 2020 which regulates volatile organic compounds (VOC) in cleaning agents (GB 38508-2020). The regulation was released as a national standard in March 2020, followed by implementation on December 1st 2020.

The standard provides limit requirements for VOC, test methods and package marks of cleaning agents. This standard is applicable to cleaning agents containing VOC produced and used in industrial production and service activities. This standard is NOT applicable to cleaning agents used in aerospace, nuclear industry, military industry and semiconductor (including integrated circuit) manufacturing. These areas of industrial production are exempted.

Perchloroethylene (PERC) is listed in this standard and therefore falls under this restriction. According to the standard, cleaning agents with a content of ≥ 20% of PERC may for example not be used in industrial production and service activities. Cleaning agents with a VOC content of ≥ 900 g/L may not be used in industrial production and service activities. The standard also defines the limit of VOC content in a cleaning product and therefore alternative formulations are needed in order to meet the requirement.

PERC supplied by SAFECHEM in China can only be used in the industries exempted from the standard, which include aerospace, nuclear industry, military industry and semiconductor (including integrated circuit) manufacturing.