Saccharin is an FDA-regulated food additive permitted in specific food categories under 21 CFR. Imported saccharin intended for food use must meet FDA purity specifications, and the foreign manufacturer should be registered with FDA. Finished food products containing saccharin must carry the previously required warning statement, though Congress has since removed the mandatory label requirement for the ingredient itself.

Imides contain two carbonyl groups flanking a nitrogen atom (–CO–NH–CO–), as in saccharin or phthalimide, while imines contain a carbon-nitrogen double bond (C=NH or C=NR) without the flanking carbonyls. The functional group present — imide vs. imine — determines the subgroup, and the compound's structural formula or IUPAC name is the definitive classification reference.