9 CFR § 310.16 - Disposition of lungs.
(a) Livestock lungs shall not be saved for use as human food.
(b) Lungs found to be affected with disease or pathology and lungs found to be adulterated with chemical or biological residue shall be condemned and identified as “U.S. Inspected and Condemned.” Condemned lungs may not be saved for pet food or other nonhuman food purposes. They shall be maintained under inspectional control and disposed of in accordance with §§ 314.1 and 314.3 of this subchapter.
(c) Lungs not condemned under paragraph (b) of this section may be used in the preparation of pet food or for other nonhuman food purposes at the official establishment, provided they are handled in the manner prescribed in § 318.12 of this subchapter, or they may be distributed from the establishment in commerce, or otherwise, in accordance with the conditions prescribed in § 325.8 of this subchapter for nonhuman food purposes or they may be so distributed to pharmaceutical manufacturers for pharmaceutical use in accordance with §§ 314.9 and 325.19(b) of this subchapter, if they are labeled as “Inedible [SPECIES] Lungs - for Pharmaceutical Use Only.” Otherwise, they shall be disposed of at the official establishment, in accordance with §§ 314.1 and 314.3 of this subchapter.