There was an article on the Times website concerning the health risks of using BKT…even the ones that claim to be formaldehyde free.
Some high points:
Responding to complaints from workers, OSHA found evidence of dangerously high levels of formaldehyde in the air of salons using these hair-straightening products — even though the products are often listed as “formaldehyde free.” The agency also found evidence of allergic reactions by workers and clients to the products, including nosebleeds and eye irritation.
In a memorandum filed recently in court — which you can read here [PDF] — California says that state testing has shown that Brazilian Blowout Smoothing Solution contains approximately 8% formaldehyde by weight, which “is in the range typical of embalming fluid used by funeral homes.”
There’s a larger problem at issue here. In Europe, more than 1,000 chemicals have been banned for use in cosmetics, many of them carcinogens and reproductive toxicants. In the United States, only eight (or nine by some counts) substances have been restricted or banned by the FDA, because that agency is underfunded and impotent when it comes to real regulation. The system is perfectly designed to let something like the Brazilian blowout get to market without much blowback.