Your question of whether a line of products – including all types of exterior and interior surface coatings – may lawfully be used in direct or indirect food contact applications is one that can be answered only on a case-by-case basis by evaluating each substance in the coating in light of the intended purpose. Coatings used in direct food contact (i.e., on the surface of the package that may contact food) and in indirect food contact applications (i.e., on the nonfood contact surface of the package) may be regulated under the Food and Drug Administration's (FDA) authority over food additives. In this regard, the question of whether substances used in the coating are properly defined as "food additives" and, therefore, subject to FDA's regulations turns on whether they may become "components" of food; that is, whether the coating substances are reasonably expected to migrate to food at detectable levels under the intended conditions of use.

There are a large number of substances – including some with grease and moisture resistant properties – that are currently authorized for various food contact coating applications under FDA's indirect food additive regulations. See, for example, Title 21 of the Code of Federal Regulations (C.F.R.) § 175.300 (identifying substances that may be used in coatings for metal substrates or repeated use articles); § 175.320 (listing substances that may be used in coatings for polyolefin films); and § 176.170 (authorizing certain substances for use in coatings for paper and paperboard). Listings in these regulations for the various substances may contain use level limitations, food type or temperature restrictions, or other restrictions. The listings in these regulations must be reviewed carefully to ensure they are consistent with the intended end uses of the coatings. In addition to the food additive regulations in 21 C.F.R., components of coatings may be permitted based on an effective Food Contact Notification, prior sanction, or Threshold of Regulation exemption, or on the basis that the coating component is exempt from the need for such a listing because it is considered to be generally recognized as safe (GRAS).

In summary, an evaluation of whether a coating on a substrate (whether used in direct or indirect contact with food) may be used in compliance with FDA's regulations must be conducted on a case-by-case basis, taking into account the full composition of the coating and its intended conditions of use. Each component of the coating must have a suitable FDA status for the proposed use. For more information on FDA's food packaging and indirect food additive regulations, please visit the PackagingLaw.com articles, Food Packaging Regulation in the United States and the European Union, Fathoming Food Packaging Regulations Revisited, and What's Under the Coat of Section 175.300?.