Hair relaxers change the appearance of hair by altering its chemical makeup. During the relaxing process, the chemical bonds of the hair are broken then reformed into a straight, relaxed pattern. The chemicals used in the process — sodium hydroxide, lithium hydroxide or guanidine hydroxide, — Lye Relaxers are made with Sodium Hydroxide mixed with water, petroleum jelly and emulsifiers to create a creamy consistency.
How can chemicals “relax”, or straighten hair? Well first of all, as assumed, the chemical would need to be potent enough to do so. Both lye and “no lye” hair relaxers are very strong chemicals that work in the same manner by changing the basic structure of the hair shaft.
HOW CHEMICAL HAIR RELAXERS WORK ON YOUR HAIR
When the chemical solution is applied on your hair either by a professional in a salon, or at home with your home relaxer kits, the (caustic “lye cream”) chemical penetrates the cortex or cortical layer and loosens the natural curl pattern.
It swells open the hair’s fibers, penetrates the protein structure of the hair and weakens its internal bonds, causing the natural curls to loosen out. This then alters the entire hair structure causing it to change by this action. The chemical melts down the protective layer of the hair shaft. Leave it for too long or apply too much and the hair will turn to a mushy paste and melt off which is the corrosive nature of the chemicals.
The Human hair is the subject of a remarkably wide range of scientific investigations. Its chemical and physical properties are of importance to the cosmetics industry, forensic scientists, and to biomedical researchers.
Hair is made of keratin – a protein found in also in nails and skin. It is keratin that gives hair its strength and elasticity.
Each strand of hair is made of 3 parts. Cuticle, Cortex and Medulla.
Cuticle is the outer layer of the hair strand and looks like scales on a fish or tiles on a roof. They are colourless, transparent and easily damaged. The Cuticle layer protects the hair strand. The Cortex makes up the main bulk of the hair strand. This is the place where all the chemical and physical bonds of the hair are found. The bonds determine the elasticity, texture and curl of the hair. The Medulla is the central part of the hair strand consisting of cells filled with air spaces. A medulla is present in most hairs with the exception of thin hair.
Our main concern in chemical relaxing process is the Cortex as this is what gives the hair its curl, strength and elasticity. It contains the bonds which affect our chemical relaxing process. The bonds are 3 types – Disulphide bonds, Salt bonds and Hydrogen bonds. The Disulphide /Sulphur bonds are the strongest and can only be broken when chemical hair relaxers are applied to the hair.
When the chemical hair relaxer is applied to the hair shaft, it causes the cuticle to swell allowing the product to penetrate into the cortex of the hair. This then breaks the Sulphur bonds releasing one atom of the sulphur bond and replacing it with a new bond lanthionine. The hair now has one sulphur and one lanthionine bond. Once this bond has been broken, the hair has now lost its natural shape and resistance and is now straight. This is what has altered the natural curl of the hair strand. Thus, when you use chemicals to make curly hair straight, you have not only changed the natural pattern of the hair but you have also lost its strength and elasticity. The action of using chemical hair relaxers on the hair has been likened to burning wood into ash where it cannot become wood again. This is one of the problems about using relaxers as once you’ve applied them to your hair, there’s no turning back. There’s no way to reverse the process except to work with new growth. The degree to which the hair is successfully straightened depends on the type and strength of chemical used, the time it’s left in the hair, and the underlying health or weakness of the hair being treated. The treated portion of the hair moves away from the scalp as the new growth of untreated hair sprouts up from the roots, requiring periodic retreatment (about every 6–8 weeks) to maintain a consistent appearance.
The ingredient Sodium Hydroxide is at the extreme end of alkalinity on the pH level of 13 and 14. Healthy hair and skin has a pH factor of around 4.5 to 5.5. If it is exposed to something more acidic or on a lower pH than itself, it hardens, becomes brittle and burns off when at the extreme end of the acidic scale – hydrochloric acid. In general, the more the percentage of sodium hydroxide used, the higher the pH level and the quicker the chemical reaction will take place on the hair, and this leads to the greater the danger of hair damage.
Misuse by an untrained person or an uncaring professional, however, can lead to severe consequences, including chemical burns, hair damage, breakage and hair loss.
Before beginning any hair treatment, especially one that introduces chemicals to your hair, you owe it to yourself to be well informed. Armed with a better understanding of this process, you will be able to make good decisions with regard to hair and scalp care.
Chemical relaxers generally is dangerous but in an untrained hands is worse and is a recipe for untold disaster. Caustic soda on hair is like putting bleach on clothes. These dangerous ingredients are corrosive and if left on the hair longer than required will melt the hair which explains why your hair does not get any straighter but thinner as it continues to melt away the protective layers of the hair strand.
One must keep in mind that relaxers do not help the hair, but actually strip it. So by applying chemicals to the hair, even if it is to achieve a desired effect, is never really to the benefit of your hair health.