About the poly inner itself, you need to ensure that it’s not PVC , which is produced by artificial softeners. Polyethylene has no softeners, which can leach into paper or onto the vinyl, and though low-grade polyethylene can produce a white dust,
HDPE sleeves will not. The poly lining lowers static electricity and reduces wear and tear in the handling of the disc, as well as being resistant to solvents, bases, acids and oxidants.