term used by manufacturers to indicate their products are safe for use with photographs• not currently regulated

This is a term similar to archival quality but more specific to materials used with photographs. Acid-free is the determining factor for a product to be labeled photo-safe.

This term is generally used in place of the term acid-free when a manufacturer can't legally claim that a product is acid-free. As a rule of thumb, it's a good idea to avoid products that claim to be photo safe rather than acid-free.