On May 15, 2026, Thailand’s Ministry of Industry officially issued a draft amendment to the Hazardous Substances List and opened it for public consultation, with the comment period ending on June 15, 2026. The draft aims to further fulfill Thailand’s international obligations as a State Party to the Chemical Weapons Convention (CWC) and strengthen controls over specific hazardous substances.
Background
Pursuant to document S/1820/2019 issued by the Organisation for the Prohibition of Chemical Weapons (OPCW) on December 23, 2019, the 24th Conference of the States Parties to the CWC approved on November 27, 2019 the addition of four new Schedule 1 chemicals (Nos. 13 to 16) to the Annex on Chemicals to the Convention. This decision entered into force for all States Parties on June 7, 2020.
As a State Party to the Convention, Thailand’s Department of Industrial Works (DIW) convened the National Coordination Committee Meeting No. 1/2021 on March 25, 2021, and unanimously agreed to propose to the Hazardous Substances Committee that these four newly added chemicals be classified as Type 4 hazardous substances under the purview of the DIW.
Currently, hazardous substances controlled under the CWC are scattered across Annex 5.1 and Annex 5.5 of the Ministry of Industry’s Hazardous Substances List and its amendments. The coexistence of multiple lists may affect regulatory effectiveness. For this reason, Thailand’s Ministry of Industry deems it necessary to adjust the relevant hazardous substances.
Main Contents of the Draft Amendment
- Deletion of certain substances from Annex 5.1
A total of 43 hazardous substances will be deleted from Annex 5.1 and reclassified into Annex 5.5. This adjustment is solely for the purpose of facilitating classification management in accordance with the CWC and does not affect their status as hazardous substances subject to control under the Hazardous Substances Act B.E. 2535 (1992) and its subordinate laws.
- Renaming of Annex 5.5
Annex 5.5 will be renamed “Substances Controlled under the Chemical Weapons Convention”. This annex will contain a total of 1,378 hazardous substances.
- Addition of 4 new controlled chemicals to Annex 5.5
Four chemical substances added to the CWC Schedules in 2019 (covering a total of 144 chemical items) will be added to Annex 5.5 and designated as “Type 4 hazardous substances.” Once the draft amendment is approved, these four substances will be subject to strict controls. Under the Hazardous Substances Act, their production, import, export, or possession will be prohibited.
The four substances are:
- No. 13: P-alkyl (H or ≤C10, including cycloalkyl) N-(1-(dialkyl (≤C10, including cycloalkyl) amino)) alkylidene (H or ≤C10, including cycloalkyl) phosphoramidic fluorides and their corresponding alkylated or protonated salts
- No. 14: O-alkyl (H or ≤C10, including cycloalkyl) N-(1-(dialkyl (≤C10, including cycloalkyl) amino)) alkylidene (H or ≤C10, including cycloalkyl) phosphoramidic fluorides and their corresponding alkylated or protonated salts
- No. 15: Methyl-(bis(diethylamino)methylene)phosphoramidic fluoride
- No.16:Carbamates (quaternary and bis-quaternary ammonium salts of dimethylcarbamoyloxypyridine)
Relevant responsible agencies, importers, exporters, manufacturers, holders, and transit transporters may submit their comments to Thailand’s Ministry of Industry before June 15, 2026. The Department of Industrial Works will be responsible for the subsequent classification and regulation of hazardous substances.
