Japan’s Ministry of Health, Labour and Welfare, Ministry of Economy, Trade and Industry, and Ministry of the Environment jointly issued a notice outlining new provisions for the handling of chemical substances containing Class I Specified Chemical Substances as impurities. Class I Specified Chemical Substances are those whose manufacture, import, and use are generally prohibited. The new regulations will take effect on April 1, 2026, and the previous notice issued on October 6, 2025, will be repealed as of March 31, 2026.
Under the Chemical Substances Control Law (CSCL), the Best Available Techniques (BAT) principle applies to Class I Specified Chemical Substances that are generated as by-products during the manufacture of chemical substances. Based on this principle, the level of Class I Specified Chemical Substances should be reduced to a level that is “technically and economically feasible in industry.” According to the Notice on the Application of the CSCL, when a Class I Specified Chemical Substance present as an impurity is deemed unlikely to cause harm to human health through environmental pollution, and its content has been reduced to a technically and economically feasible level, that impurity may be excluded from being treated as a Class I Specified Chemical Substance.
For chemical substances already reported as being managed under the BAT principle, they will not be treated as Class I Specified Chemical Substances under the CSCL. However, companies must continue to implement appropriate management and information transfer to prevent environmental contamination from such substances. Furthermore, companies that had already submitted a written report prior to this notice, based on the 2019 notice, including a self-management limit value along with measures to reduce the content of the relevant Class I Specified Chemical Substance, will still be considered compliant with the relevant regulations.
Companies’ Obligation to Submit Written Reports
If a company finds that a chemical substance it manufactures or contains as an impurity trace amounts of a Class I Specified Chemical Substance (excluding hexachlorobenzene, polychlorinated biphenyls, and short-chain chlorinated paraffins), it must set its own self-management limit value based on the BAT principle and submit that value along with reduction measures in writing to the three ministries. In addition, companies must continuously verify whether the content exceeds the limit and continue efforts to reduce it.
Specific Benchmark Values Set for Hexachlorobenzene
For tetrachlorophthalic anhydride (TCPA) and pigments or dyes made from TCPA as a raw material, trace amounts of hexachlorobenzene (HCB) are generally known to be present as an impurity. The notice stipulates that the benchmark value for HCB content in TCPA is 200 ppm, and for pigments or dyes made from TCPA as a raw material, it is 10 ppm. Companies that manage HCB levels within these benchmark values based on the BAT principle will be deemed compliant and are not required to submit periodic reports.
Management Standards for Polychlorinated Biphenyls and Short-Chain Chlorinated Paraffins
For trace amounts of polychlorinated biphenyls (PCBs) present as impurities, companies must implement management based on the BAT principle and submit prior written documentation. Proper management within the range of not exceeding 50 ppm will be deemed compliant, without the need for periodic reporting.
For short-chain chlorinated paraffins (SCCPs), in line with decisions under the Stockholm Convention, companies must implement management based on the BAT principle for levels below 1% by weight (10,000 ppm) and submit prior written documentation.
Separate Provisions for Plastic Recycled Materials
For recycled plastic materials manufactured partly using post-consumer plastics, if they contain Class I Specified Chemical Substances for which international management values have been set, companies must manage them based on the BAT principle and submit prior written documentation.
The three ministries have stated that for self-management limit values already submitted, companies must report on their management status as requested and conduct re-evaluations as appropriate over time.
