The Organic Materials Review Institute (OMRI) reviews applications from companies that want a third-party verification that their product is suitable for use in organic production, processing, or handling according to the USDA National Organic Program (NOP) guidelines. OMRI listing is voluntary and not appearing on the OMRI list doesn’t necessarily mean that the product is not suitable for organic farming. For more information on OMRI listing, see omri.org.
The Washington State Department of Agriculture (WSDA) also reviews materials and lists ones that they find acceptable. WSDA fee schedule is lower than OMRI, so you may see products listed WSDA Organic.
Producers can self certify that their products meet NOP organic standards. Basically if all the ingredients are from a natural source, the product is NOP. Some artificial chemicals are also acceptable under NOP standards. There are a few products that are natural that are not NOP – for example, strychnine and nicotine. For more information on what is and isn’t allowed by the NOP, refer to the USDA website.
I am in the process of updating Rincon-Vitova Insectaries product descriptions to show whether the product is acceptable for organic use and if it is OMRI or WSDA certified, NOP acceptable, or Natural-Not Regulated (the designation for beneficial insects, microbes or nematodes with no restricted additives).