News broke at the end of last year that Brazilian straightening treatments contain formaldehyde (even those that claim to be formaldehyde free). Formaldehyde is the same ingredient used for embalming and is a known carcinogen, which means that it can cause cancer and a host of other very serious health concerns. More and more stylists who perform straightening treatments regularly have come forward complaining of nose bleeds, eye irritation, and breathing difficulties.
Since then, many salons have stopped offering Brazilian straightening treatments—but not all of them. Clients still want the smooth, straight hair these treatments guarantee, and they’re willing to take the risk and pay hundreds of dollars to get them done. Some salons find it too hard to turn them away.