Environment Ministry adds 11 hazardous substances to Marine Pollution Order

The Ministry of the Environment, via Ministry of the Environment Notice No. 43 dated October 5, 2026, has revised the substances designated by the Minister of the Environment based on the provisions of items (b) and (d) of Appended Table 1 of the Order for Enforcement of the Act on Prevention of Marine Pollution and Maritime Disaster (Cabinet Order No. 201 of 1971), newly designating eleven substances, including tetrakis(hydroxymethyl)phosphonium sulfate, as harmful substances. The revision is based on a determination by the Marine Environment Protection Committee of the International Maritime Organization and applies from the date of promulgation. The notice was issued by the Minister of the Environment, Hiroyoshi Sasagawa.

The target of the revision is a portion of Ministry of the Environment Notice No. 148 of December 2006, which defines the designated substances. Under the framework regulating the discharge of harmful liquid substances other than oil from ships, this notice lists a “coefficient” for each substance, which is used for regulatory calculations. This revision was carried out as a procedure to reflect the determination made by the Marine Environment Protection Committee of the International Maritime Organization in the domestic designations.

Eleven Newly Designated Substances and Their Coefficients

In the appended table of the notice, the following substances have been newly listed, each with an assigned coefficient:

• Tetrakis(hydroxymethyl)phosphonium sulfate — Coefficient 100
• Brown grease — Coefficient 100
• Polyethylenimine containing propylene oxide — Coefficient 25
• N-alkyl-N,N,N-trimethylammonium chloride — Coefficient 1,000
• Didecyldimethylammonium chloride — Coefficient 1,000
• Benzyltoluene — Coefficient 25,000
• Diethylene glycol butyl ether solution of a polymer of adipic acid added with chloromethane, 2,2-(methylimino)bis(ethanol), and di-(9Z)-9-octadecenoic acid ester — Coefficient 10
• Dialkylaminophosphonic acid solution — Coefficient 0
• Phosphinic acid — Coefficient 0
• Polyacrylic acid solution — Coefficient 0
• Polyaspartic acid amine — Coefficient 0

Limitations of Scope Based on Concentration and Composition

Some substances were designated with limitations on the concentration or composition of the solution.

• Polyethylenimine containing propylene oxide is limited to a diethylene glycol monoethyl ether solution with a concentration of 78% by weight.
• N-alkyl-N,N,N-trimethylammonium chloride is limited to those where the number of carbon atoms in the alkyl group is between twelve and sixteen, and mixtures thereof.
• Dialkylaminophosphonic acid solution is limited to those with a concentration of 45% by weight or more and 55% by weight or less.
• Polyacrylic acid solution is limited to those with a concentration of 48% by weight or less.

Amendment Procedures and Jurisdiction Applicable from the Date of Promulgation

The amendment applies from the date of promulgation, with October 5, 2026, as published in the Official Gazette, serving as the starting point. The Ministry of the Environment holds jurisdiction, and the notification was issued in the name of the Minister of the Environment. A tabular method of amendment has been adopted, where substances with no corresponding provisions in the “Before Amendment” column are newly added, and provisions with no corresponding entries in the “After Amendment” column are deleted.

Practical Impact on the Shipping and Chemical Industries

Due to this designation, ship operators transporting or discharging the target substances, as well as chemical businesses manufacturing or handling them, will become subject to regulations as harmful liquid substances. Since the coefficients relate to regulatory calculations, they may affect practical operations regarding cargo handling, cleaning, and record-keeping. As this designation reflects the determinations of the International Maritime Organization, it is positioned as a measure to ensure consistency with international regulations.

Sources

• Ministry of the Environment Notification No. 43 (October 5, 2026, Minister of the Environment Hiroyoshi Sasagawa)
• Order for Enforcement of the Act on Prevention of Marine Pollution and Maritime Disaster (Cabinet Order No. 201 of 1971) Appended Table 1, Items (b) and (d)
• Ministry of the Environment Notification No. 148 of December 2006 (Partial Amendment)
• Official Gazette, published Monday, October 5, 2026