OMRI = Organic Materials Research Institute. This is the organisation that works hand-in-hand with the US Dept of AG to review and recommend that products be given Approval for use in Organic Meat and Vegetable production. They were in existence long before the USDA had a formal program, and now that USDA has a formal program, OMRI is used by the USDA to provide continuity.

AZOMITE™ is registered in the USA as an anti caking agent. It is GRAS (Generally Recognized As Safe) by the FDA and may be used in animal feed at up to 2% (weight:weight).