All stabilizers contain directly or indirectly Formalin save in processes such as Kodak's E-6 chain where the Formalin is in the pre-conditioner and not in the final rinse. Products such as Tetenal's C-41 STAB which claim to be Formalin free are while technically free of Formalin contain Hexamethylenetetramine (Hexamin) which degrades into ammonia and formaldehyde. Some like Champion's final rinse is even more complicated designed to be useable even in non-plumbing chain. They address concern for occupational exposure to Formalin but aren't really "healthier". With modern films one could probably use glutaraldehyde or some other protein fixative. Formalin, however, remains one of the cheapest and most effective solution. In the volumes we as "amateurs" are using I think its a non-issue. Yes, bathing in large quantities of formalin is not "healthy" but the exposure in the small amounts our darkrooms see of these low concentration rinses is very minor. I'm just guessing but I'd expect the metabolistic contract with Formalin is probably significantly higher among cigarette smoke (even probably 2nd hand) or the amount "gassed out" by a new set of cheap bookshelves or cabinets using particleboard. And that's nearly marginal compared to the amount of carcinogens--- Formalin is concerned, at most, a potential human carcinogen--- people merrily spew out from their motorcars.
Originally Posted by srs5694