Chemistry in your cupboard

Hair perming

The process of perming (short for ‘permanent waving’) of hair is based on the same chemical principles as hair removal.

Hair is placed in rollers to hold it into the required curly shape and a product containing alkaline glycollate ions, Figure 17, is applied to the hair which opens up its structure, breaks sulfur-sulfur bonds and ‘loosens’ the protein structure in a similar way to that described above.

Figure 17: Structure of glycollate ion.

The difference is that an oxidising agent (usually hydrogen peroxide) is then applied to re-form the S-S bonds in new positions and ‘lock’ the hair permanently in its new shape, Figure 18.

Figure 18: Permed hair is created using the same chemical principles as hair removal.