Safety Considerations for Permanent Waves

As for other reactive hair products, the primary safety concerns for permanent waves generally arise from misuse or failure to comply with the product s usage instructions. Skin irritation, hair breakage, oral toxicity, sensitization, and scarring alopecia either have been reported in the hterature or are referred to in the warning instructions for home permanent-wave products. 

An older, but relevant review of the toxicity of thiol home permanent waves and neutrahzer solutions was published by Norris in 1964 [139].Thio-glycolates are moderately toxic yet comparable to bisulfite. Sodium thio-glycolate has a LD50 of 148mg/kg (i.p. in rats) [140] versus 115mg/kg (i.v. in rats) for sodium bisulfite [141]. 

Thioglycolate waving lotions can irritate skin [142] however, irritation in home use is rare and may in part be related to the alkalinity of the system 

Although ammonium thioglycolate has been reported as having a low sensitization potential [145], a few incidents of sensitization have been reported among hairdressers where contact is frequent [145]. 

8th Int. Hair-Science Symp., Kiel, Germany (1992). 

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