On March 26, 2026, Japan's Consumer Affairs Agency (CAA) issued Notification No. 159 of the Consumer Base, amending and correcting the roster of monomers that make up the base materials governed by the positive-list system for food utensils, containers and packaging. The changes took effect the same day, adding two newly permitted essential monomers for resin makers and fixing a misclassification in the amide-polymer category. Manufacturers of food contact materials should update their formulations and compliance checks against the revised annexes.
The notification revises the document "Monomers etc. constituting the base materials specified in Table 1 of Appended Table 1" of the Specifications and Standards for Foods, Food Additives, Etc. (MHLW Notification No. 370 of 1959), the master instrument that underpins Japan's synthetic-resin positive list for food contact materials. CAA said the additions were made at the industry's request, widening the menu of building blocks available for compliant resins, while the correction removed an error that had crept into one annex.
Two new essential monomers were inserted, each under the polymer family to which it belongs. For both families, the existing rule is unchanged: the listed alcohols and acids (for ester-bond polymers) or amines and acids (for amide-bond polymers) must together account for at least 50 mol% of the polymer's constituents.
Newly Added Essential Monomers
|
Polymer family (annex) |
Newly added essential monomer |
|
Annex 1-12 |
Polymers mainly with ester bonds; 4-hydroxybutyric acid added to the acid list |
|
Annex 1-17 |
Polymers mainly with amide bonds, including those made chiefly from aziridine or 2-ethyl-2-oxazoline; 1,5-pentanediamine added to the amine list |
Separately, CAA corrected the categorisation within Annex 1-17. "Hydrogenated and dimerized unsaturated fatty acids" (limited to C18 fatty acids) had been wrongly placed among the amines; it is now relocated to the acids list, where it properly belongs, so that the amide-polymer monomer table no longer misleads formulators.
For the food contact industry, the practical effect is that two more monomers can now be built into compliant ester- and amide-based resins without a separate authorisation, as long as the 50 mol% threshold is met, while the reclassification cleans up the amide-polymer roster. Resin manufacturers and food contact material brand owners should review their raw-material specifications against the revised Annexes 1-12 and 1-17 and confirm that any product relying on the reclassified fatty-acid entry is now matched to the correct category.
