For years women have been using hair straightening treatments that contain formaldehyde, a probable carcinogen according the to FDA.
Unfortunately, these products are not regulated. Two years ago, federal health authorities warned salon owners and stylists about the cancer risk associated with regular exposure to formaldehyde but the public never heard about it. Obviously, salon workers are most at risk, but the public remained unaware that every time they blew dry their hair they were exposing themselves to this chemical.
Colors of Cold Spring Harbor salon owner Linda Schenck says that whenever someone came into her salon who had a Brazilian elsewhere she would get sick and have to leave. Just applying color or blow drying released the chemical.