Microbial fats and oils are produced by microorganisms — including fungi, bacteria, or microalgae — through fermentation, rather than being extracted from conventional plant tissue. Classification under 151630 requires that the fat or oil originate from a microbial source; oils derived from macroalgae or conventional oilseeds would fall under different headings. When the biological origin is ambiguous, supporting documentation such as a certificate of origin or technical data sheet from the manufacturer is essential.

Because these are novel food-grade ingredients, importers should be prepared to provide FDA with a detailed product description, the producing microorganism's identity, processing method, and any applicable GRAS determination or food additive petition. Prior notice to FDA is required for all food shipments. Admissibility and classification of these products can be complex; consulting a licensed customs broker and regulatory counsel is strongly advised.