How is the Cross-Reference in Section 175.300 Interpreted?
What is the right interpretation of "Substances the use of which is permitted by regulations in this part" found in Section 175.300 (b)(3)? This article states that "Any substance employed in the production of resinous and polymeric coatings that is subject of a regulation in subchapter B of this chapter and conforms with any specification in such regulation." This suggests that the substance listed in Sec. 175.105 (Adhesives)are also applicable for coatings (175.300) notwithstanding the fact that the title of Subpart B says "Substances for use only as components of adhesives". Is this the right assumption or do I have to conclude that for coatings only the compositions/substances mentioned under 175.300 are approved?
Title 21 of the Code of Federal Regulations (C.F.R.) Section 175.300 specifically addresses resinous and polymeric coatings. You are correct that this section includes a list of cleared substances for use in the manufacture of these coatings, in addition to permitting substances that are generally recognized as safe (GRAS), prior sanctioned, or the subject of another food additive regulation provided that the substance, when used in coating applications, complies with the specifications and limitations listed in the cross-referenced regulation. Although the wording of the regulation would seem to suggest that you can use any substance cleared in any food additive regulation, in fact, FDA intended to include by cross reference only those substances covered by a regulation that would permit their use in a coating. Thus, the list of cleared substances listed in 21 C.F.R. 175.105 (Adhesives) are cleared only for adhesive formulations intended for the packaging, transporting, or holding of food. They would not on that basis be permitted for use in coatings.
Therefore, there are substances other than those listed in 175.300 that may be used in resinous and polymeric coatings, however the substances listed in 175.105 are not cleared by FDA for use in these coatings. For more information, see the PackagingLaw.com articles: What's Under the Coat of Section 175.300? and FDA Regulation of Adhesives in Food Packaging.