Toxic ingredients: sodium hydroxide, calcium hydroxide, guanidine carbonate, guanidine hydroxide, thioglycolic acid, lithium hydroxide. A relaxer must be used with a neutralizing shampoo and conditioner whether applied at home or in a salon. Conventional shampoos and conditioners found in hair straightening kits contain the same ingredients found in conventional shampoos and conditioners, whose health effect are detailed in those sections.
Possible health effects of relaxers and activators are scalp irritation, skin burns, permanent scarring, deep ulcerations, skin drying and cracking, dermatitis, irreversible baldness, eye damage including blindness and weak, dry, broken and damaged hair.
Relaxers, whether with or without lye, have a very high pH (very near the top of the scale). In other words, they are caustic. Relaxers break the hair down. Relaxers work because they break the bonds that actually give strength to the hair. This causes the hair to straighten. Therefore, relaxed hair is, by definition, weaker than natural hair. Relaxers also deplete the hair of sebum (the oil your scalp secretes). Combine that with heat and you can really end up with a problem. Hair that has been straightened will be weaker than if it were natural and will be more prone to problems.
For years, the main chemical used has been sodium hydroxide - a powerful alkaline caustic otherwise known as lye. Sodium hydroxide is used in products like Draino to dissolve hair in drains. It's also used in depilatories to dissolve hair.
Lately, new "no-lye" products have been introduced. While the chemicals in these products are not lye, they are very similar and have the same effect, chemically, on the hair. Advertising leads people to believe these chemicals are much safer when in fact they are only slighter better.
"People may think because it says 'no lye' that it's not caustic," says US Food and Drug Administration (FDA) biologist Lark Lambert. But both types of relaxers contain ingredients that work by breaking chemical bonds of the hair, and both can burn the scalp if used incorrectly. Lye relaxers contain sodium hydroxide as the active ingredient. With "no lye" relaxers, calcium hydroxide and guanidine carbonate are mixed to produce guanidine hydroxide.
Research has shown that this combination in "no lye" relaxers results in less scalp irritation than lye relaxers, but the same safety rules apply for both. They should be used properly, left on no longer than the prescribed time, carefully washed out with neutralizing shampoo, and followed up with regular conditioning. The FDA has received complaints about scalp irritation and hair breakage related to both lye and "no lye" relaxers. -- LessToxicGuide.ca