21 C.F.R. § 582.3637 – Potassium metabisulfite.

(a) Product. Potassium metabisulfite.
(b) [Reserved]
(c) Limitations, restrictions, or explanation. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice, except that it is not used in meats or in food recognized as source of vitamin B1.