This standard specifies the terms and definitions, basic principles, selenium content requirements, and inspection methods of ecological selenium-rich foods (edible agricultural products) in Kaiyang County. This standard applies to ecological selenium-rich and selenium-containing edible agricultural products produced through planting (breeding) in Kaiyang County, as well as ecological selenium-rich and selenium-containing prepackaged foods processed with them. It does not apply to products that add selenium during processing. Fortified foods.