Japan Revises Guidance on Trace Impurities of Class I Specified Chemical Substances under CSCL
Reference source : Ministry of Economy, Trade and Industry (METI) Portal - Japan
On 26 October 2026, Japan’s Ministry of Health, Labour and Welfare (MHLW), Ministry of Economy, Trade and Industry (METI) and Ministry of the Environment (MOE) published revised guidance on the handling of Class I Specified Chemical Substances present as trace impurities under the Chemical Substances Control Law (CSCL). This revision introduces a new concentration threshold for medium-chain chlorinated paraffins (MCCPs) and clarifies the management requirements for trace impurities.
Key Updates from the Guidance
The revised guidance establishes the following thresholds for specified substances present as impurities:
- Polychlorinated biphenyls (PCBs): 50 ppm or less.
- Hexachlorobenzene (HCB): 200 ppm or less in tetrachlorophthalic anhydride (TCPA); 10 ppm or less in other substances.
- Short-chain chlorinated paraffins (SCCPs): Below 10,000 ppm.
- Medium-chain chlorinated paraffins (MCCPs): 30,000 ppm or less.
Previous Update in March 2026
Earlier ministries issued guidance on 31 March 2026, which is repealed from 26 October 2026. Previously submitted management proposals remain recognised under the earlier provisions.
Enforcement Date and Stakeholder Obligations
The revised guidance became effective on 27 October 2026. Manufacturers and importers must set up Best Available Technology/Techniques-based self-management limits. They must also submit impurity reduction measures to the three ministries before any manufacture or import. For substances that fall under the specified thresholds companies must use the Form 1 or Form 2 as required. Companies are responsible for monitoring impurity concentrations continuing to reduce impurities where reporting their management status when asked and sharing impurity levels, in Safety Data Sheets (SDSs) with downstream users.
