Are Hair Products Safe in Pregnancy?

Studies show that the use of hair products during pregnancy does not increase the risk of adverse fetal effects compared with the general population. (1) It is estimated that having hair treatments 3 to 4 times during pregnancy is pretty safe due to minimal systemic absorption. (1) However, the safety of these products comes with limited exposure. (2)

It is important for women who are pregnant and work as hairdressers to assure their safety and that of their unborn infant by: wearing gloves, working less than 35 hours a week, and avoiding prolonged standing. (1)

In a study published by the American Journal of Epidemiology in 1999, researchers performed a case-control study on 525 Black women in North Carolina. These women had delivered infants following exposure to either hair straightening or curling products. The study concluded that the use of these products during pregnancy was not associated with preterm delivery or low birth weight. (3)

Chemicals are used in hair products to either color, straighten, relax, curl, or bleach hair. The following is a list of the most common chemicals used in hair coloring:

  • Phenylenediamine
  • 3-aminophenolresorcinol
  • toluene-2,5-diaminesulphate
  • sodium sulfite
  • oleic acid
  • sodium hydroxide
  • ammonium hydroxide
  • propylene glycol
  • isopropyl alcohol

Additionally, these are products most often used in hair straighteners and permanents:

  • Sodium hydroxide
  • Guanidine hydroxide
  • Ammonium thioglycolate
  • Ammonium hydroxide
  • Petroleum
  • Hydrogen peroxide

References:

1. Chua-Gocheco A, Bozzo P, Einarson A. Safety of hair products during pregnancy: personal use and occupational exposure. Can Fam Physician. Oct 2008;54(10):1386-1388.
2. Hueston WJ, Eilers GM, King DE, McGlaughlin VG. Common questions patients ask during pregnancy. Am Fam Physician. May 1 1995;51(6):1465-1470.
3. Blackmore-Prince C, Harlow SD, Gargiullo P, Lee MA, Savitz DA. Chemical hair treatments and adverse pregnancy outcome among Black women in central North Carolina. Am J Epidemiol. Apr 15 1999;149(8):712-716.