All commercially manufactured hair products contain preservatives to keep them fresh and to inhibit the growth of bacteria and fungi. May of these chemicals can also cause dry, itchy scalp and skin. Here are some commonly used preservatives that are known to cause skin irritation:
- Benzyl alcohol
- Imidazolidinyl urea
- Diazolidinyl urea
- Sodium Hydroxylmethylglycinate
- Methyl, Propyl, Butyl and Ethyl parabens
- Phenoxyethanol
- DMDM hydantoin
- Quaternium-15
- Methylisothiazolinone
