What paths do we have to take to get FDA compliance for an inorgani
What paths do we have to take to get FDA compliance for an inorganic additive that we intend to add to fibre packaging and plastic packaging, e.g. it would be an "indirect food additive." My understanding for plastic packaging is if it is not listed under 21 CFR we would have to go down the path of FCN/FAP unless it is classified as "exempted from evaluation." The way it is exempt from evaluation is if we can prove it does not migrate into food via the FCN migration techniques (chemistry section). Is the above approch correct for plastics? What about fibre/paper?
Yes. The approach you have described is essentially correct and works with respect to additives for plastic or paper.
Typically, the first step in the analysis is to determine whether the additive currently is the subject of a food additive regulation, prior sanction, Threshold of Regulation exemption, or effective Food Contact Notification (FCN). If the additive is not the subject of one of these clearances for its intended use, we then determine whether it is subject of one or more exemptions or exclusions under the Federal Food, Drug, and Cosmetic Act. These exemptions and exclusions include the determination as to whether the material is properly considered a "food additive" as that term is defined under the Act or whether the substance may be considered GRAS (generally recognized as safe). The former determination may be made first by calculating "worst-case" potential for migration. If this is not successful, then migration studies generally conducted in accordance with FDA guidelines may be recommended. A GRAS analysis usually entails an assessment of dietary exposure relative to the toxicological database that may be available for a substance.
If neither of these approaches is successful, the available exposure and toxicology data may nonetheless be sufficient for FDA to determine that the additive is safe by way of the Food Contact Notification or Threshold of Regulation process. Additional information on the methods available to establish a substance's regulatory status can be found in our web article, Fathoming Food Packaging Regulations.