On May 20, 2019, China's National Health Commission (NHC) published the long-awaited draft of Food Safety National Standard Adhesives for Use in Food-Contact Materials and Articles ("draft Adhesives Standard") forpublic comments.[1] The draft Adhesives Standard applies to adhesives used in food-contact applications and proposes the following definition for "Adhesives Used in Food-Contact Materials and Articles":
"Materials that create adhesion by physical or chemical mode in food-contact materials and articles, directly or indirectly in contact with food."
The draft Adhesives Standard classifies adhesives into two categories: direct food-contact and indirect food-contact. The standard includes a positive list of base polymers for use in both categories that can be found in Annex A. Specifically, Table A.1 contains 68 substances for use in both direct and indirect food-contact adhesives (30 substances are listed in GB 9685-2016; 3 substances originated from the prior hygiene standards; and 5 substances[2] are from administrative announcements). Table A.2 contains 236 substances for indirect food-contact adhesives (198 from GB 9685-2016 and 38 from administrative announcements).
The draft Adhesives Standard proposes some general requirements on the use of adhesives. It states that enterprises shall strictly control the design and manufacture of the seams and edges of food-contact materials and articles and take measures, such as effective barriers, to reduce the residual levels of direct food-contact adhesives in food, and the migration of indirect food-contact adhesives to food. Further, enterprises shall control the oligomers generated during the manufacture of adhesives to ensure that their migration to food does not endanger the human health.[3]
As we have seen in other food-contact materials standards, the draft Adhesives Standard also sets forth sensory and physicochemical specifications, i.e., overall migration limit (OML), potassium permanganate consumption, and heavy metals. In addition, a specification of ≤ 0.01 mg/kg for primary aromatic amines (PAA) applies to aromatic polyurethane adhesives, epoxy adhesives that use amine-type curing agents, and polyimide adhesives that may generate PAA during the curing process. These types of adhesives are also subject to additional labelling requirements. The draft Adhesives Standard specifies that the migration test, including that for PAA, should be performed on finished food-contact materials and articles. Similar to existing standards for other food-contact materials, the draft Adhesives Standard requires that the labeling of adhesives comply with GB 4806.1 General Safety Requirements for Food-contact Materials and Articles.
1 See http://www.nhc.gov.cn/sps/
2 Informal communication with the authority confirms that the actual number of substances approved by administrative announcements is 35.
3 The Drafting Notes accompanied to the standard explains as follows: "Given that the components of adhesives are complicated, and there are a certain percentage of reaction type adhesives, NIAS such as oligomers may be generated during not only the curing process but also adhesion process, which may have safety risk and is necessary to be controlled."