9 CFR §325.19

1. (a)To specimens of product sent to or by the Department of Agriculture or divisions thereof in Washington, DC, or elsewhere, for laboratory examination, exhibition purposes, or other official use;
2. (b)To material released for educational, research and other nonfood purposes, as prescribed in § 314.9 of this subchapter;
3. (c)To glands and organs for use in preparing pharmaceutical, organotherapeutic, or technical products and not used for human food, as described in § 318.1(g) of this subchapter;
4. (d)To material or specimens of product for laboratory examination, research, or other nonhuman food purposes, when authorized by the Administrator, and under conditions prescribed by him in specific cases; and
5. (e)To articles that are naturally inedible by humans, such as hoofs, horns, and hides in their natural state.