Whether you need a disguise to run from the law or are just trying to emulate *NSYNC-era
frosted tips, you may need some chemical assistance to put that hue in your do.
So, calling all bottle blondes and box brunettes!
Get ready to learn everything you’re dyeing to know about the chemistry of artificial
hair color.
Human beings around the world have colored their hair since ancient times with vinegar,
nutshells, berries and even lead—yikes.
The story of salon hair color really has its roots in the history of modern chemistry.
In 1907, French chemist Eugène Schueller marketed an artificial hair color formulation
using para-phenylenediamine, or PPD, a compound still used in some hair dyes today.
In fact, Schueller’s company, the French Harmless Hair Dye Co., later became known
as L’Oreal.
To understand how today’s hair color works, we’ll need to review some basic hair anatomy—and
no, I’m not talking about the mullet.
Each strand of hair grows from a hair follicle, a surprisingly complex organ complete with
an arrector pili muscle that gives us goosebumps and a sebaceous gland that secretes oil.
But all of that is what lies beneath the skin’s surface.
The visible part of hair—ya know the stuff you brush, braid, fade or pull into a man
bun—is known as the hair shaft.
The shaft is covered by a layer of overlapping keratin cells called the cuticle, which protect
and waterproof the inner layers of the hair.
Non-permanent dyes that come in sprays and gels coat the cuticle but usually fade after
a few shampoos.
To get that color to permanently last, we need to penetrate that cuticle and allow dye
to reach an inner layer of the hair shaft called the cortex.
The cortex contains more keratin plus important pigment proteins called melanins, which give
hair its natural color.
To make this happen, salons bring out the big guns.
That means developer—a fancy salon term for hydrogen peroxide—mixed into a solution
containing chemicals called primary intermediates, coupling compounds, or “couplers., and ammonia.
When the mixture is applied to hair, the ammonia is responsible for some of those signature
nostril-tingling scents of hair dye and is also extremely basic.
Like... platinum ombré on Stacy basic.
With a PH of over 11, the solution causes the entire hair shaft to swell.
This separates the keratin cells that make up the cuticle and allows the dye molecules
to seep into the cortex.
And now, for the mane event.
As our mixture penetrates the tens of thousands of hair shafts on your head, hydrogen peroxide
lightens the natural pigment and takes away electrons from, or oxidizes, the dye’s “primary
intermediate” compounds.
These chemicals, like Schueller’s PPD give off colorful reactive species when oxidized
—not unlike how iron turns red when it oxidizes to rust.
Darker hair colors are achieved by using a higher concentration of primary intermediates,
while lighter dyes let hydrogen peroxide do most of the work.
But whether you’re a summer, a winter or are going all in for a cosplay, the primary
intermediates also react with the dye’s “couplers” to fine tune and achieve that
perfect shade.
There are dozens of coupling compounds that can alter the exact tone But we’re not gonna
split hairs here, most are alcohols and amines that interact with primary intermediates to
produce large, complex dye molecules.
Dye companies usually mix and match couplers to achieve the intended tint and tone.
Think of them like Bob Ross adding a happy little highlight to your luscious locks.
And as a hair icon, he should know.
Once the ammonia is washed out, the cuticle cells fall back in place and the dye molecules
are locked in—leaving you with a glorious head of permanent color.
Unfortunately, as the ammonia leaves the hair and the keratin layer reforms, the scaly cells
may not fit together as neatly as before.
This spells damage for your hair fibers, and you might notice your locks are a bit more
fragile.
Swapping ammonia for alternative alkaline agents like ethanolamine may help prevent
some of this damage, but they may also limit the hues you can choose.
Dyed hair can also be prone to dullness between touch-ups—primarily because free radical
oxygens left behind in the dying process or even released by the induction of the sun’s
UV rays can degrade your new pigment and the hair cuticle itself.
To fight this, some color-protecting shampoos contain antioxidants to help clear the free
radicals and help keep that shine.
To keep that coif gram-worthy, you might also want to avoid chemicals that can shift your
new hue.
For example, blondes will want to steer clear of copper—often used as an anti-algae compound
in swimming pools—which can oxidize their pigment to create a green tint.
Yeah, I’m afraid that patina looks a lot cuter on the Statue of Liberty.
Want more?
We also get into the hairy details of shunning shampoo and explain why redheads may be more
sensitive to pain.
Thanks for watching, and be sure to like and subscribe on your way out.
See you next week.