title: Ask the doctor. I had my hair straightened six months ago.  Is there any danger in getting these treatments twice a year?  I hear they may contain formalin or formaldehyde.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Olbricht
mesh_terms: D002170:Canada; D003257:Consumer Product Safety; D003358:Cosmetics / Q000008:administration & dosage / Q000633:toxicity*; D005557:Formaldehyde / Q000008:administration & dosage / Q000633:toxicity*; D006197:Hair; D006203:Hair Preparations / Q000008:administration & dosage / Q000633:toxicity*; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D012449:Safety; D014481:United States
chemical_list: D003358:Cosmetics; D006203:Hair Preparations; D005557:Formaldehyde