Ammonium sulfate is listed by AAFCO (the Association of American Feed Control Officials) as a mineral feed additive. Does this mean it’s allowed in organic production?

by Deder Siedler

Ammonium sulfate, (NH4)₂ SO₄, is an additive occasionally used in both livestock and human foods. While ammonium sulfate is often considered a source of nitrogen, it is also a source of sulfur.

The NOP Rule states that synthetic “Trace minerals, for enrichment or fortification…” (§205.603 (d)(2)) and “Vitamins, for enrichment or fortification…” §205.603 (d)(3)) are Allowed, but only when “FDA approved.”

Traditionally, OMRI and other certifiers cited FDA regulations in 21 CFR 582 (subpart F) and 21 CFR 573 as evidence that a substance is “FDA approved”. However, there are substances that do not appear in these FDA regulations that are allowed under §205.603 (d)(2). In 2002 The NOSB issued a recommendation that:

“The National List annotations be changed to allow for synthetic vitamins and minerals contained in Section 205.603(d)(1) and (2) by broadening the annotations to include materials either listed in the CFR or in Sections 57 or 90 on the AAFCO Official Publication…”, with the exception of any poultry or mammalian slaughter by-product, which would be an obvious violation of the livestock feed standard in §205.237.

While this update to the National List was never implemented, the Memorandum of Understanding (MOU) between the FDA and AAFCO allows OMRI and certification bodies to approve substances defined by AAFCO as “FDA approved” and allowed at §205.603(d)(2) and (3). Since Ammonium sulfate is cited in Section 57.27 of AAFCO, it is allowed.

OMRI has previously written on the relationship between AAFCO and the FDA. For more information, see https://www.omri.org/aafco.

Revised and updated in April 2019 by OMRI Technical Director Doug Currier. This article was originally published in the Summer 2016 edition of the OMRI Materials Review newsletter.