Hair Chemical Curling Permanents

 

Chemical Curling Permanents

The incidence of using chemical curling agents or perming in some countries such as the United State and United Kingdom is relatively low (~10%), but it is higher in Asian countries such as Japan (~20%). The majority of perms are performed by stylists because the risk of damage from these treatments can be high.

The chemistry involves breaking of cysteine disulfide bond, typically with thioglycolic acid, followed by arrangement of hair into a desired configuration and then reforming the disulfide bonds with hydrogen peroxide, setting the style in place. The bond reforming is not 100% effective, so internal strength will always be reduced by these treatments. In addition, hair types will respond to perming chemistry differently.

Consequently there is no fixed time for the initial bond breaking stage. Stylists are skilled to stop the chemistry before the hair structure is severely compromised. In situations where excess chemistry is used, hair will become easy to break and additional broken fibers will be noticed after treatments (Figure 1.36).