I first heard of the problems that this product was causing while I was in Oregon for training. A hairdresser who had been using this product a lot now cannot do hair at all because of the damage it has done to her lungs. She actually started bleeding from her ears and nose. I couldn't believe what I was hearing and that we, the consumer, had not been protected or warned of the dangers hidden in this treatment. In fact, the company itself still denies that it does contain formaldehyde, and the educators and other professionals fall for and back up this bogus lie. What is most likely happening is that these companies are using some sort of derivative of formaldehyde that the FDA doesn't regulate as of yet.
Lots of companies do this kind of thing in all sorts of industries. For example, if anyone says that their permanent hair color is "ammonia free," they are lying. There is no such thing. Permanent hair color has to have ammonia in it to color your hair. If they claim that their product doesn't, then their company is using a derivative of ammonia and most likely this derivative is stronger and more damaging than any other color that does contain regulated amounts of ammonia.