Final answer:
The sulfites used in low-pH hair relaxers are compatible with pleasant product characteristics, including ease of rinse, skin safety, slight acidity, and harmlessness to hair. They function by altering disulfide bonds in hair through a chemical reaction, which allows for a permanent reshaping of the hair structure.
Step-by-step explanation:
The sulfites used as low-pH hair relaxers are formulated to be compatible with certain desired properties for hair care products. In permanent waving, a chemical process alters the disulfide bonds in hair keratin to achieve a change in hair texture. Initially, a reducing agent such as ammonium thioglycolate is applied, which reduces the disulfide bonds and allows the hair to be reshaped. After styling the hair on rollers, an oxidizing agent like hydrogen peroxide is applied to reform the disulfide bonds, securing the hair in the new shape.
The characteristics of sulfite-based hair relaxers include properties like producing a pleasing foam, ensuring ease of rinsing, minimizing skin and eye irritation, and providing a thick or creamy feeling. They should also have a pleasant fragrance, low toxicity, good biodegradability, be of slight acidity (pH less than 7), and not cause damage to the hair, potentially even repairing damage. This reaction is an example of a Lewis acid-base reaction where sulfur oxides act as Lewis acids with various oxides and hydroxides to form sulfites or sulfates.