Harris Food Grade Diatomaceous Earth Feed Supplement 10 lb. is composed of 100% ground freshwater DE, also known as fossil shell flour, with no additives. Harris (DE) is made of the naturally occurring fossilized remains of diatoms, mined in Nevada but bagged in Georgia. Harris Diatomaceous Earth is listed with the Organic Minerals Research Institute (OMRI) for organic use. Included in the re-sealable bag is a powder duster, allowing for easy application of a fine dusting of powder. Always follow label instructions and keep out of reach of children.