Permanent waves, or as they are normally known, perms, is the
result of a chemical process on hair to make curls.
In order to permanently change the shape of the hair, it is necessary
to alter a number of disulfide bonds.
There are different types of perms available. However, they are
all largely based on two kinds of reducing agents: thioglycolates
and bisulfites. In this way, all permanent waving solutions involve
a similar chemical principle. The permanent waving process starts
with hair washing. Subsequently, curlers are arranged on the hair
in accordance to the degree of curl wanted. Then, the permanent
waving solution is administered on the hair. In order to alter
disulfide bonds, the permanent waving solution has to reach the
cortex through the cuticle, which is done by using alkaline reductive
solutions. These lift the scales of the cuticle. Ammonia and ammonium
hydroxide are the most common alkali agents. The reducing agent,
that is, thioglycolates or bisulfites, split some of the disulfide
bonds, but not too many because, otherwise, the hair will not
properly recover. When the bonds are ruined, new bonds are created.
The permanent waving solution is then rinsed off, and a neutralizing
solution solidifies the bonds through re-oxidation. This neutralizing
solution most usually contains hydrogen peroxide as oxidative
agent. Finally, the cuticle scales go back to their original position.
Some unwanted outcomes of permanent waving may include swelling
and longitudinal contraction. Actually, these can continue after
the rinsing and neutralizing of the permanent waving solution.
Another result of permanent waving could be the characteristic
smell, which may persist for days or even weeks after the treatment.
To elude these irritation reactions and odor, it is imperative
to avoid washing for several days as the permanent waving “heals”.
Gloves are compulsory for the technician or the person who practices
the permanent waving.
Because chemicals are harsh in nature, contact with the skin
should be avoided or, at least, minimized. Permanent waving that
is not well practiced will most probably result in no longer elastic
and flexible hair, but brittle and fragile. At this stage, even
combing will produce hair loss. However, hair will grow again.