Chemical Straightening

Chemical Straightening
It estimated around 70 % of Black women relax their hair.  However, alarmingly approximately  67%  of which, will suffer a side effect ranging from breakage, being the most common to shedding; to alopecia’s ; to  chemical burns. Long-term use of relaxers is also implicated as a factor in the development of Central Centrifugal Cicatricial Alopecia, and believed to be a factor in the development of severe contact dermatitis.

The Structure
The structure of hair consists of polypeptide chains connected by ends bonds and interlinked with side bonds. There are 3 types of side links: disulfide bonds, salt bonds and hydrogen bonds, all of which work together to form an incredibly strong structure.
Disulphide bonds are the strongest links and account for about a third of the hair’s strength. Hair relaxers work by altering the chemistry of these bonds.

The Process
Relaxer creams have a high alkalinity level which is required to open the hair cuticle and allow penetration of the chemicals into the shaft. Once inside, the chemical reactions break the cross bond attachment allowing the polypeptide chain to be free to adopt its new shape. Hence wise your hairdresser must continually smooth your hair to coerce the chain into the required straightened position.  Neutraliser is then applied to deactivate the chemical reaction and normalise the pH level.
Sodium hydroxide, also known as lye, is commonly found in relaxers as it by far the most effective straightener. Nevertheless, the pH of Sodium Hydroxide can exceed 13.0, whereas the normal pH of hair is 5. It is an extremely corrosive chemical also used in hair depilatories, as well as drain pipe cleaners due to its effectiveness strength.   Other chemicals used tend to be marketed as No-Lye products, using chemical such as guanidine hydroxide, but work very much on the same principle. Although these may reduce scalp irritation, they tend to have a higher pH than sodium hydroxide. They also tend not to straighten the hair as well and so retouching is required more frequently. In addition, no-lye relaxers work by removing moisture from the cortex causing the hair to become dry and porous. So overall these have the potential to be more damaging. Unfortunately for some, once the disulfide bonds are broken not all reform cross links, leaving the hair in a weaken state.
However, some of his damage can be prevented by undertaking a thorough evaluation of the hair type and condition before applying a relaxer. This should consist of 3 tests:

• Elasticity Test
Strong hair exhibits good elasticity, whereas reduced elasticity indicates a pre -treatment regime is required before continuing with a relaxer.                

• Strand Test
This provides an indication of the outcome, particularly in terms of elasticity. If the hair shows signs of reduced elasticity and breaks easily, then the relaxer should be delayed and a treatment programme followed.

• Porosity Test
Ideally should be undertaken on different sections of the head to assess cuticle damage. Damaged cuticles feel very rough in texture as opposed to the smoothness of healthy strands.

Overall while relaxer applications can be damaging to the hair, the key to prevention is, knowing your hair type and the type of relaxer you intend using. With proper care, conditioning and understanding, you can help to avoid the pitfalls which affect the majority of women who relax their hair.