This action imposes restrictions or prohibitions on substitutes for ozone-depleting substances (ODSs) under the U.S. Environmental Protection Agency's (EPA) Significant New Alternatives Policy (SNAP) program. SNAP implements section 612 of the Clean Air Act, as amended in 1990, which requires EPA to evaluate substitutes for the ODSs to reduce overall risk to human health and the environment. Through these evaluations, SNAP generates lists of acceptable and unacceptable substitutes for each of the major industrial use sectors. The intended effect of the SNAP program is to expedite movement away from ozone-depleting compounds while avoiding a shift into substitutes posing other environmental problems. On March 18, 1994, EPA promulgated a final rulemaking setting forth its plan for administering the SNAP program, and has since issued decisions on the acceptability and unacceptability of a number of substitutes. In this Final Rule (FRM), EPA is issuing its decisions on the acceptability of certain substitutes included in a May 21, 1997 notice of proposed rulemaking. Specifically, this action clarifies the criteria for unique fittings used in motor vehicle air-conditioning systems, and addresses the acceptability of certain substitutes in the fire suppression, solvent, and aerosol sectors, and the unacceptability of substitutes in the refrigeration and air conditioning, solvents, aerosols, fire suppression, and adhesives, coatings, & inks sectors.