This rule would propose a determination as to whether n-propyl bromide (nPB) is an acceptable substitute for Class I and Class II ozone depleting substances used in a number of uses including cleaning aerosol and carrier solvent uses adhesives and coatings. EPA previously listed nPB as an acceptable solvent in metals, electronics, and precision cleaning (May 30, 2007; 72 FR 30142) and proposed to list nPB as unacceptable for the aerosol solvent and adhesives end-uses and acceptable subject to use conditions for the coatings end-use (May 30, 2007; 72 FR 30168). Since the issuance of those earlier rules, there is significant new information available concerning toxicity and industrial hygiene standards for this chemical, and EPA has issued or proposed additional requirements for this chemical under other EPA programs. If found acceptable, this would provide industry with another alternative to solvents with higher ozone depletion potential. An acceptability determination could include specific conditions on the use of nPB in these uses for the purpose of ensuring that nPB is used in a manner that is as safe and environmentally protective as other available substitutes., OSHA does not currently regulate nPB. If we determine that nPB cannot be used safely in a specific end use, as compared with other substitutes available for that end use, we would find it unacceptable.