The U.S. Department of Agriculture (USDA) National Organic Program (NOP) issued on March 24, 2015, a policy memorandum clarifying the status of nanotechnology in organic production and handling under the USDA organic regulations.  The memorandum states that NOP has received questions about the use of nanotechnology.  The memorandum uses the term “engineered nanomaterials” to refer to substances specifically designed and manufactured to have unique properties or behavior attributable to particle size.  The term “incidental nanomaterials” is used to refer to substances that are incidental byproducts of other manufacturing (e.g., homogenization, milling) or that occur naturally.  The memorandum states that no engineered nanomaterial will be allowed for use in organic production and handling unless the substance has been:  (1) petitioned for use; (2) reviewed and recommended by the National Organic Standards Board (NOSB); and (3) added to the National List of Allowed and Prohibited Substances through notice and comment rulemaking.  The memorandum notes that to avoid conflicts about the presence of nanomaterials in substances regulated by other federal agencies, NOP is not establishing a separate definition for engineered nanomaterials.  Instead, the descriptions in the U.S. Food and Drug Administration’s (FDA) Guidance for Industry Considering Whether an FDA-Regulated Product Involves the Application of Nanotechnology and the U.S. Environmental Protection Agency’s policies on regulating pesticides that use nanotechnology and control of nanoscale materials under the Toxic Substances Control Act “should be used as applicable.”