PART 423—ENVIRONMENT, SUSTAINABLE ACQUISITION, AND MATERIAL SAFETY Authority: 5 U.S.C. 301 and 40 U.S.C. 486(c). Source: 89 FR 81015, Oct. 7, 2024, unless otherwise noted. Subpart 423.1—Use of Recovered Materials and Biobased Products 423.107 Agency affirmative procurement programs. The USDA affirmative procurement program (APP) policy applicable to all USDA agencies and staff offices is hereby established. Components of the APP are in the USDA Contracting Desk Book Part 423. Subpart 423.3—Notice of Radioactive Material 423.301 Requirements. The HCA shall establish a system of instructions to identify the installation/facility radiation protection officer. Subpart 423.6—Notice of Radioactive Material 423.601 Requirements.