Before getting into what is bleach, why do we bleach and of course how do we bleach our hair it’s important to understand the anatomy of hair, how our hair works and what does it consist of.
While scientists have always argued that human hair is an evolutionary remnant, however, human hair do serve a lot of physiological and psychological functions. Human hair grows at a rate of 0.35 mm of hair per day, and around 100 hairs are being shed on a daily basis. Human hair angiogenesis begins at about ten weeks of gestation, and final development results in the mature hair follicle. In biological terms, hair follicle looks like a tunnel-shaped structure situated in the epidermis (outer layer of the skin). Hair growth starts at the bottom of the hair follicle. The root of your hair is made up of protein (keratin) and derives its nutrition by blood from the blood vessels on the skin. As more cells are created, the hair grows out of the skin and reaches the surface. Sebaceous glands near the hair follicles produce oil, which nourishes the hair and skin.
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What determines our hair colour?
Hair colour is determined by the amount of a pigment called melanin in hair. Hair and eye colour are mostly determined by our genes. But it’s not just by the genes we have, but also by whether those genes are turned on or turned off. And since genes can turn on and off throughout our lives, this means your hair colour can change.
Genes are the instruction manuals for cells, and just like anything else our cells can do, there are genes that have the instructions for making melanin. All cells in your body have the gene for melanin. But not all cells are using this instruction manual.
For example, the cells on your palms and bottom of your feet don’t need to make melanin. In these cells, the melanin genes are “turned off.” This is why these parts of your skin are lighter than everywhere else. They just aren’t using the pigment genes.
The genes for making melanin might turn on or off over the course a person’s lifetime. If this happens in the cells at the bottom of your hairs, your hair might change colour.
The most important genes here are ones that make pigment, which is what gives hair its colour. The type and amount of melanin in hair is determined by many genes, although little is known about most of them. The best-studied hair-colour gene in humans is called MC1R. Hair colour ranges across a wide spectrum of hues, from flaxen blond to coal black. Many genes other than MC1R play a role in determining shades of hair colour by controlling levels of eumelanin and pheomelanin. Some of these genes, including ASIP, DTNBP1, GPR143, HPS3, KITLG, MLPH, MYO5A, MYO7A, OCA2, SLC45A2, SLC24A5, TYRP1, TYR, ERCC6, GNAS, HERC2, IRF4, OBSCN, SLC24A4, TPCN2, and MITF, are involved in the production of melanin in hair. Some of these genes are associated with gene transcription (which is the first step in protein production), DNA repair, the transport of substances (such as calcium) across cell membranes, or the structure of hair follicles. Several of these genes contribute to eye and skin colour, but the exact role they play in determining hair colour is unknown.
Can hair colour be changed without bleach?
Hair and eye colour are mostly determined by our genes. But it’s not just by the genes we have, but also by whether those genes are turned on or turned off. And since genes can turn on and off throughout our lives, this means your hair colour can change!
But what causes these genes to be turned on or turned off?
Many different factors can turn hair pigment genes on and off. These factors are not even completely understood by scientists.
Changes in hair colour in kids and teenagers are most likely due to the change in hormones. Hormones are chemical signals that the body uses to send messages between different body parts. The various changes in hormone levels can cause pigment genes to be turned on or turned off.
The most important genes here are ones that make pigment, which is what gives hair its colour (melanin).
Hair colour can change over time. Especially in people of European descent, light hair colour may become darker as the person grows older. For instance, blond-haired children most of the time their hair gets darker by the time they are teenagers. Researchers speculate that certain hair-pigment proteins are activated as children grow older, perhaps in response to hormonal changes that occur near puberty. Almost everyone’s hair will begin to turn gray as they age, although when it happens and to what extent is variable. Gray hair is partly hereditary and may vary by ethnic origin; it is also somewhat dependent on external factors such as stress. A group of 14 participants wrote a ‘stress diary’, rating their level of stress each week. The researchers then compared this with the colour data from their hair. The researchers noticed a strong correlation between the stressful periods and hair turning grey.
They were also shocked to find that some hairs had regained their pigmentation when the stress was lifted. There was one individual who went on vacation, and five hairs on that person’s head reverted back to dark during the vacation, synchronized in time.
A 2020 study of mice suggested that stress-related greying was an irreversible process caused by the loss of stem cells in hair follicles. However, the researchers believe that the process must be different in humans. Hair becomes gray when the hair follicle loses its ability to make melanin, but exactly why that occurs is not clear.
It can also happen to teenagers due to vitamin deficiencies white and gray hairs that may start to grow at any age, and may be caused by a range of different factors.
Any deficiencies of vitamin B-6, B-12, biotin, vitamin D, or vitamin E can contribute to premature graying.
One 2015 report in the journal Development notes various deficiency studies on vitamin D-3, vitamin B-12, and copper and their connection to graying hair. It finds nutritional deficiencies affect pigmentation, suggesting colour can return with vitamin supplementation.
A 2016 study reported in the International Journal of Trichology looked to factors related to premature graying in young Indians under 25 years of age. It found low levels of serum ferritin, which stores iron in the body, vitamin B-12, and the good cholesterol HDL-C were common in participants with premature hair graying. Anyone who has white hair resulting from a vitamin deficiency should consume more foods loaded with those vitamins.
For instance, seafood, eggs, and meats are good sources of vitamin B-12, and milk, salmon, and cheese are excellent sources of vitamin D.
Vitamin supplements that are available over the counter can also correct deficiencies.
Is bleach the only chemical that can change the hair colour?
Actually no, have you ever spent the entire summer in the pool and have your hair turn green? This is from the chlorine in the pool water. Chlorine is also a very reactive chemical and will react with the copper pipes that flow water in and out of the pool. Chlorine is so reactive that it will dissolve some of that copper into the pool water you are in. When that copper gets on your hair your hair will turn green, shocking right?
That being said let me explain how bleach works before getting into how to bleach your hair.
The history of bleach
Bleaching back then was used for only clothes, the earliest form of bleaching involved spreading fabrics and cloth out in a bleach field to be whitened by the action of the sun and water. In the 17th century, there was a much significant industry of cloth bleaching in the west of Europe, using alternating alkaline baths (generally lye) and acid baths (such as lactic acid from sour milk, and later diluted sulfuric acid). The whole process lasted up to six months.
Bleaches which are chlorine based were invented in Europe in the late 18th century, which fastened that process from months to hours. The swedish chemist Carl Wilhelm Scheele discovered chlorine in the 1774, and in 1785 the French scientist Claude Berthollet recognized that it could be used to bleach fabrics. Berthollet also discovered sodium hypochlorite, which became the first commercial bleach, named Eau de Javel (“Javel water”) after the borough in Paris where it was produced. Scottish chemist and industrialist Charles Tennant proposed in 1798 a solution of calcium hypochlorite as an alternative for Javel water, and patented bleaching powder (solid calcium hypochlorite) in 1799. Around 1820, French chemist Antoine Germain Labarraque discovered the disinfecting and deodorizing ability of hypochlorites, and was instrumental in popularizing their use for such purpose. His work greatly improved medical practice, public health, and the sanitary conditions in hospitals, slaughterhouses, and all industries dealing with animal products.
Louis Jacques Thénard first produced hydrogen peroxide in 1818 by reacting barium peroxide with nitric acid. Hydrogen peroxide was first used for bleaching in 1882, but did not become commercially important until after 1930. Sodium perborate as a laundry bleach has been used in Europe since the early twentieth century, and became popular in North America in the 1980s.
Types of bleaches
Most industrial and household bleaches belong to three broad classes:
Chlorine-based bleaches, whose active agent is chlorine, usually from the decomposition of some chlorine compound like hypochlorite or chloramine.
Peroxide-based bleaches, whose active agent is oxygen, almost always from the decomposition of a peroxide compound like hydrogen peroxide.
Sulfur dioxide based bleaches, whose active agent is sulfur dioxide, possibly from the decomposition of some oxosulfur anion.
Let’s get more into details of the most used types.
Chlorine based bleaches can be found in various household bleach products, as well as in specialized products that are particularly made for hospitals, public health, water chlorination, and industrial processes.
The grade of chlorine based bleaches is often expressed as percent active chlorine. One gram of a 100% active chlorine bleach has the same bleaching power as one gram of elemental chlorine.
The most common chlorine-based bleaches are:
Sodium hypochlorite (NaClO), found as a 3–6% solution in water, usually called “liquid bleach” or just “bleach”. Back then called “Javel water”. It is used in many households to whiten laundry, sanitize hard surfaces in kitchens and bathrooms, treat water for drinking and keep swimming pools free of infectious agents which cause diseases.
Bleaching powder (Also known as “chlorinated lime”), usually a mixture of calcium hypochlorite (Ca(ClO) 2), calcium hydroxide (slaked lime, Ca(OH) 2), and calcium chloride (CaCl2)
in variable amounts. Sold as a white powder or in tablets, is used in many of the same applications as sodium hypochlorite, but is more stable and contains more available chlorine.
Chlorine gas (Cl2).
It is used as a disinfectant that plays part in water treatment, especially to make drinking water and in large public swimming pools. It was used extensively to bleach wood pulp, but this use has decreased tremendously due to environmental threats.
Chlorine dioxide (ClO2).
it is an unstable gas that is generated in situ or stored as dilute aqueous solutions. It finds large-scale applications for the bleaching of wood pulp, fats and oils, cellulose, flour, textiles, beeswax, skin, and in a number of other industries.
Other examples of chlorine-based bleaches, used mostly as disinfectants, are monochloramine, halazone, and sodium dichloroisocyanurate.
Peroxide-based bleaches are characterized by the peroxide chemical group, namely two oxygen atoms connected by a single bond, (–O–O–). This bond is easily broken, giving rise to very reactive oxygen species, which are the active agents of the bleach.
The main products in this class are:
Hydrogen peroxide itself (H2O2).
It is used, for example, to bleach wood pulp and hair or to prepare other bleaching agents like the perborates, percarbonates, peracids, etc.
Sodium percarbonate (Na2H3CO6), an adduct of hydrogen peroxide and sodium carbonate (“soda ash” or “washing soda”, Na2CO3).
Dissolved in water, it yields a solution of the two products, that combines the degreasing action of the carbonate with the bleaching action of the peroxide.
Sodium perborate (Na2H4B2O8).
Dissolved in water it forms some hydrogen peroxide, but also the perborate anion (B(OOH)(OH)− 3)
which can perform nucleophilic oxidation.
Peracetic (peroxoacetic) acid (H3CC(O)OOH).
Generated in situ by some laundry detergents, and also marketed for use as industrial and agricultural disinfection and water treatment.
benzoyl peroxide ((C6H5COO) 2).
It is used in topical medications for acne and to bleach flour.
Ozone (O3), While not properly a peroxide, its mechanism of action is similar. It is used in the manufacture of paper products, especially newsprint and white Kraft paper.
Potassium persulfate (K2 S2O8) and other persulfate salts. It, alongside ammonium and sodium persulfate, are common in hair lightening products.
Permanganate salts such as Potassium permanganate (KMnO4).
In the food industry, other oxidizing products like bromates are used as flour bleaching and maturing agents.
Sodium dithionite (also known as sodium hydrosulfite) is one of the most important reductive bleaching agents. It is a white crystalline powder with a weak sulfurous odor. It can be obtained by reacting sodium bisulfite with zinc
2 NaHSO3 + Zn → Na2S2O4 + Zn(OH)2
It is used as such in some industrial dyeing processes to eliminate excess dye, residual oxide, and unintended pigments and for bleaching wood pulp.
Reaction of sodium dithionite with formaldehyde produces Rongalite,
Na2S2O4 + 2 CH2O + H2O → NaHOCH2SO3 + NaHOCH2SO2
which is used in bleaching wood pulp, cotton, wool, leather and clay.
In Reversal processing, residual silver in the emulsion after the first development is reduced to a soluble silver salt using a chemical bleach, most commonly EDTA. A conventional fixer then dissolves the reduced silver but leaving the unexposed silver halide intact. This unexposed halide is then exposed to light or is chemically treated so that a second development produces a positive image. In colour and chromogenic film, this also generates a dye image in proportion to the silver.
Photographic bleaches are also used in black-and-white photography to selectively reduce silver to reduce silver density in negatives or prints. In such cases the bleach composition is typically an acid solution of potassium dichromate.
How does the bleach work?
Bleach breaks down the pigment from your hair shaft through the process of oxidation. It is impossible to make your hair a lighter shade without the help of a bleaching (or oxidising) agent.
Hydrogen peroxide (H2O2) and ammonia (NH3) are the most commonly used bleaching agents and they are often mixed together. They are often mixed together, because when used separately, they are unstable and very slow in bleaching the hair. Do not be tricked by manufacturers who use ‘peroxide-free’ labels as a way to promote their products as a hair friendly product. Although these mixtures do not contain peroxide, they will contain another oxidizing agent, which can be just as damaging to your hair.
How to bleach your hair
Put in mind that this process do cause damage for your hair, and for the same reason, your hair needs to be in a healthy condition to be bleached to bear it.
If your hair is dry or damaged, try waiting a month or two before you bleach it.
If done incorrectly or carelessly, bleaching can lead to disastrous results. (like breakage, burning, and discolouration.) To ensure your hair isn’t damaged by the bleaching process, you’ll need to start preparing your hair months in advance. In the meantime, you can prepare your hair by nursing it back to health. You can start preparing your hair at least two weeks before bleaching it, and do not try to process your hair for at least three months prior to the bleaching treatment. If you have processed or dyed hair, wait for at least three months before you decide to bleach it. Because bleach works best on virgin, or unprocessed, hair, experts say that your hair is also more exposed to damage if you re-process it too early.
And put in mind that darker hair will require multiple bleaching rounds which will lead to serious hair damage in result so try to be realistic as much as possible to evade that hair damage. If you have dark hair you should plan to space out your bleaching sessions over the course of several months and yes, that means a blonde hair colour will not be instant. It could take several years to achieve your wanted hair colour. Additionally, anyone with extremely fragile or damaged hair should proceed with caution. You may have grand visions of yourself with lighter hair, but some hair types simply can’t handle bleach well, and bleaching delicate strands is often not worth the risk.
Here’s what you’ll need:
- An old T-shirt
- Hair bleach of your choice
- Some hair clips
- An old towel
- A shampoo of your choice
Make sure you put on some old clothes that you wouldn’t mind getting the bleach on. Put your gloves on. Your hair should almost always be clean and dry meaning no dry shampoo, no styling products, and no excessive oils, although a little natural oil is completely fine
The process of bleaching your hair:
- Section the hair into four quadrants in order to neatly apply product. You’ll also want to apply the bleach to smaller segments within each section to ensure you’re fully saturating the hair and having the product equally on your hair.
- Start by mixing in a bowl the bleach powder and the developer. Use 2 tablespoons of each and mix well. Developers come in different levels, that in indicate the amount of peroxide. The higher these levels, the more peroxide it has. Developer comes in different volumes, 10 being the weakest and 40 the strongest. I recommend that you start by using the 10 volume developer the first time, to see how your hair reacts to it.
- Add shampoo to the mix. Try to use the same amount you would if you would be washing your hair. Adding shampoo to the mix will make the bleaching less aggressive. If your hair is prone to dryness, add a bit of conditioner as well.
- Then, apply bleach 1 inch away from the scalp, and work down the hair section. It’s important not to start at the scalp, as it processes quicker from body heat. Once the rest of the hair is done, go back and apply bleach to the roots.
- Once you’re done, use a hair clip to keep your hair together and wrap the plastic wrap around your head and let the bleach process between 20-45 minutes, depending on your hair colour, desired results, and package directions. I recommend reading the manufacturer directions on the back of the bottle to ensure you aren’t over-processing. (Keep an eye on your hair and the surrounding skin. If you notice redness, itching, or burning after you have kept the bleach on your hair for a while, please wash the bleach off and visit a doctor.)
- Wash out the mix from your hair, rinsing thoroughly. I recommend washing your hair with a balancing shampoo to balance the pH levels of your scalp. Follow with a protein balancing conditioner. Let your hair air dry. Do not use conditioner if you’re planning to dye your hair afterwards and leave that step for after removing the dye.
After doing these steps try to have a hair routine that focuses on bringing moisture back to your hair as bleaching makes your hair more dry and rough so try to avoid by all costs blow drying or washing your hair with shampoo daily.