When you have naturally curly hair you basically
have two options. You can accept it "as is" or you
can straighten it. If you decide to straighten it
you can do it chemically or you can do it with products
that promise to tame the curls on a day by day basis.
If you decide to straighten your hair, both the
chemical and day to day versions have positive and
minus considerations. The purpose of this article
is not to discuss the pros and cons of chemical
vs non chemical straightening. The goal of this
article is to present as much information as possible
on the chemical process. This article is neither
for nor against straightening. It only presents
Karen M. Shelton
The Hair Boutique
The most common reason that people decide to have their hair straightened
is to eliminate curls. Sometimes this process will be used also
to soften or eliminate wavy hair. Chemical hair straightening,
also known as relaxing, involves a process where the basic structure
of overly curly or wavy hair is changed into a straight form.
Both relaxing and permanent waving utilize fairly strong chemicals
that are applied directly to the to the hair shaft. However, their
objectives are reversed. While a perm is designed to add curls
or waves, a relaxing treatment is designed to remove them.
Consult A Professional
Chemical hair straightening is not a difficult procedure, but
it does require a thorough technical knowledge of the relaxing
process. Therefore it should always be performed by a hair care
professional with a track record of success with straightening.
It is best to have the relaxing process performed by a professional
so that they can perform a strand test to determine the recommended
strength of the relaxer that should be used. The stylist will
also need to evaluate current hair texture, porosity, elasticity
and the presence or absence of any hair damage.
Fine, chemically lightened, or colored hair generally requires
a very mild relaxing formula. Normal, medium-textured virgin hair
can tolerate regular strength relaxers. Coarse virgin hair may
require a strong or super relaxing formula. The professional will
be able to determine the best type of relaxing formula based on
the results of a strand test and by looking at and touching the
hair to be treated.
A good professional will also keep detailed records of any chemical
relaxing treatments that have been performed on the hair and can
use those written records to determine the best course of treatment.
Hair Strand Test
A professional hair stylist that is well versed in chemical straightening
will always do a strand test on any hair that is to be treated.
This not only protects the client's hair but helps the stylist
determine the best type of formula to use, whether to use a conditioner-filler
on the hair before applying the chemicals and whether a base petroleum
protection layer is needed or not.
A strand test can be done in a variety of ways which include:
Pulling the hair to determines its degree of elasticity.
Applying a small amount of relaxer to determine the hair reactions
to the chemicals.
A finger test.
Products Used During Chemical Hair Relaxing
The following products are generally used in chemical hair relaxing
There are three basic steps that are performed during a hair
- chemical hair relaxer formula
- petroleum cream
- shampoos designed specifically for hair relaxers
- hair relaxing conditioners
The steps generally include the following:
A protective petroleum cream may or may not be applied as
protection to the scalp & previously relaxed or damaged hair.
A chemical hair relaxing formula is applied to soften, loosen
and relax the natural curls.
After the hair has "cooked" or been processed for the appropriate
time limits, the chemicals are completely rinsed from the
hair with warm water. A neutralizing formula is then applied
to the hair. The neutralization process oxidizes and restores
the hair's pH because a high pH, as a result of the relaxing,
can cause the hair to swell and break.
A conditioner is applied to the hair. Depending on the condition
of the hair to be relaxed, the conditioner may be applied
before the relaxing formula, after or sometimes it may even
be applied before and after. Two types of conditions are available.
These include the cream conditioners and the protein or liquid
Overly curly hair that contains damage from ongoing use of heat
appliances or other chemicals may need to be conditioned before
relaxer can be applied. In the case where the hair is severely
damaged, it may be best not to apply a chemical relaxer until
the hair has had a chance to recover.
In other cases a conditioner-filler is required before the chemical
relaxer can be applied to dry hair. These fillers protect hair
that may be overly porous or hair that is slightly damaged from
Sodium Hydroxide, Guanidine Hydroxide & Ammonium Thioglycolate
There are three basic types of hair relaxers. These are sodium
hydroxide and guanidine hydroxide which may or may not require
pre-shampooing, and ammonium thioglycolate, which may require
Sodium hydroxide is the strongest of the three relaxers and will
provide the most dramatic results. Sodium hydroxide is a caustic
type of chemical that actually softens hair fibers. The chemical
also causes the hair to swell at the same time. As the sodium
hydroxide solution is applied to the hair, it penetrates into
the cortical layer and breaks the cross-bonds.
The cortical layer is actually the middle or inner layer of the
hair shaft that provides the strength, elasticity and shape of
the curly hair.
Depending on various factors and the condition of the hair to
be straightened, the strength of the sodium hydroxide solution
may vary anywhere from 5 to 10 percent. The pH faction may vary
from 10 to 14. The higher the strength of sodium hydroxide, the
higher the pH and the faster the straightening solution will take
Also, the stronger the solution, the more potential damage can
occur to the hair. Sodium hydroxide contains a high alkaline content
and so special care should always be used when applying this chemical.
Guanidine hydroxide relaxers are referred to as the "no-lye" relaxers
and they tend to be less damaging than sodium hydroxide relaxers.
These products, however, still may do some damage to the hair.
It can definitely de-fat the scalp.
Guanidine hydroxide relaxers usually require conditioning treatments
before and after. These relaxers are a mixture of calcium hydroxide
cream with guanidine carbonate "activator" solution.
Ammonium thioglycolate (nicknamed "thio relaxer") is much less
drastic in its action than the sodium hydroxide and even, in some
cases, the guanidine hydroxide. It acts a little differently by
softening and relaxing overly curly hair through changes to the
hair's cystine linkage.
Thio works on the same formulation principles as thioglycolate
permanent waves. With a pH of 9-9.5, these are also considered
to be less damaging, yet still require a neutralization step.
Thioglycolate relaxers are usually in cream or gel form and can
be preceded by a pre-softener.
Since thio relaxers are considered much milder, the risk of hair
damage is also reduced by comparison to the sodium hydroxide.
Petroleum Cream/Base Cream
A protective base of petroleum cream is usually applied to the
scalp and other areas of the hair that have been previously straightened
to prevent over processing, hair breakage or burning and/or irritation
of the scalp and skin.
The protective base is applied freely to the entire scalp with
the fingers. The hairline around the forehead, nape of the neck
and over and under the ears must be completely covered. The base
should actually lay on the scalp and should not be spread or rubbed
into the skin or scalp.
The relaxer formula must never come in contact with sores or abrasions
on the scalp of the skin and should never make contact with the
The cream that is used as a base for relaxing is lighter than
regular petroleum jelly and is designed to melt at body temperatures.
As the cream melts is provides a complete protective covering
over the scalp and other desired areas with a oily film. This
film acts as a barrier against the straightening chemicals.
Some relaxing solutions are mild enough that they do not require
the protective petroleum base application. The petroleum creme
may or may not be required for the thio type of softening process.
However, it would be more likely required for sodium hydroxide
Whether a relaxing formula requires the petroleum cream or not,
it is always best to use a protective cream around the hairline
and over the delicate ear areas. It is also best to apply a base
during any chemical "retouching". It is advisable not to reapply
a straightening formula to hair that has been previously straightened
since there is a high risk of breakage or damage.
Hair Straightening Faqs Part 2.,
The Chemical Is Applied
Hair Straightening Faqs Part 3.,
this topic with others right now at the
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Thermal Reconditioning Articles By Karen M. Shelton
Gives The Inside Scoop
Founder's - Words Of Hair Care Wisdom
M. Shelton is the founder of HairBoutique.com
which has been featured in numerous magazines including
101 Celebrity Hairstyles, Today's Dallas Woman
Magazine, WE-Women's Enterprise, The National Enquirer,
American Salon Magazine and Self magazine,
as well as international publications.
Karen M. Shelton was featured in DFW Tech Biz
as winner of the Emerging CEO - Tech Titan award.
In 2001 Ms. Shelton joined 101 Celebrity Styles
& Short Cuts magazine as consumer hair editor.