8 Hair Dye Chemicals to Avoid - What You Need to Know Before You Color

Posted by KatakamiYuki on

Article updated on: November 7, 2024

Know What’s in Your Hair Dye: A Guide for Health-Conscious Consumers

Are you concerned about the impact chemical hair dyes may have on your scalp and overall health? This guide is here to help you understand and avoid commonly used chemicals in hair color products. We’ll walk you through eight ingredients frequently found in conventional hair dyes—like PPD, ammonia, and SLS—so you can check your own product’s ingredient list and make safer, more informed choices. By choosing natural or certified organic hair colors, you can reduce your exposure to potentially harmful substances, maintain healthier hair, and enjoy greater peace of mind.

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Your skin has tiny openings that allow substances, including chemicals, to be absorbed. In fact, studies on skin absorption rates of caffeine have shown that hair follicles absorb at a rate 10 times higher than the outer layer of skin.[1] With around 30,000 to 40,000 hair follicles on your scalp, it’s important to consider the chemicals present in the hair color you use.

To help protect your health, we want to help you reduce potential risks. This article shares information on common chemicals found in hair dyes and the effects they can have. We’ve compiled a list of eight chemicals often found in hair color products to help you easily identify them on the ingredient list when choosing a hair dye. By being aware of these ingredients, you can make safer, more informed choices for your hair and scalp.

chemical hair color

1. P-phenylenediamine PPD

P-phenylenediamine
PPD is short for para-phenylenediamine. It is used as a dye for dark color shades and is made from coal tar, a petroleum-derived chemical that includes benzene, naphthalene, phenols, aniline, and other chemicals. It is also used as a wood preservative, and contact with skin is best avoided.
PPD can cause reactions ranging from mild skin irritation to more severe allergic contact dermatitis.[2] Sensitive individuals may experience dermatitis—skin inflammation and irritation commonly called eczema. In more severe cases, there may be marked reddening and swelling on the scalp and the face. An allergy to PPD can result in widespread contact dermatitis, hives, and, in rare severe cases, anaphylaxis.

2. Hydrogen peroxide

Hydrogen peroxide

Hydrogen peroxide is oxygen water. It is the activator that you add to the color cream when you dye your hair. Peroxide is used as the developer or oxidizing agent. It removes pre-existing color.
Hydrogen Peroxide is said to change the hair structure and make it brittle, stripping it of its natural luster. [3]

3. Ammonia

Ammonia

Ammonia is used to open up the hair’s cuticle (the outer layer), so the dyes can come into the shaft (the inside of the hair).
Ammonia can cause skin irritation, and if it gets into your bloodstream, you could get sick. Ammonia can also impact the earth by endangering animals in the ocean and crops on the land.

4. Ethanolamine

Ethanolamine

Ethanolamine is used in our demi-permanent hair colorants instead of Ammonia.
Ethanolamine is similar to ammonia but can damage your hair more.[4] You may also notice more hair loss, and there can even be a risk of birth defects.

5. DMDM hydantoin

DMDM hydantoin

DMDM hydantoin is a formaldehyde releaser or donor. It slowly releases the chemical formaldehyde as it breaks down in the product over time to prevent mold and bacteria from growing. It works by slowing or stopping the growth of potentially harmful microbes such as fungi, yeast, and bacteria. DMDM hydantoin has come under fire in recent years because it releases small amounts of formaldehyde. It may cause tissue irritation and affect the immune system.

6. SLS

SLS

Before you use your go-to hair color, check for these ingredients: sodium Laureth sulfate, sodium lauryl sulfate, or sodium chloride. These ingredients act like a deep-cleaning detergent that can strip your hair of its new color. It strips your hair of dirt and essential, natural oils that can leave your hair weak and prone to breakage. Continuous exposure to sodium Laureth sulfate can even cause skin irritations.

7. Resorcinol

Resorcinol

Resorcinol (or benzene-1,3-diol) is a chemical commonly used in hair color, hair dyes, skin peels, and during acne treatments. It reacts with the peroxide-containing developer to give the required color or shade.
Resorcinol is a toxic dye that can cause scalp irritation and is an allergen affecting the endocrine system.

8. Methylchloroisothiazolinone

methylchloroisothiazolinone

Methylchloroisothiazolinone is a preservative in many skin care products, household cleaners, and hair dye products that stop fungi, yeast, and bacteria from growing. Methylisothiazolinone engages your immune system and irritates your skin.[5] Once this happens, you may become permanently allergic to methylchloroisothiazolinone the next time you are exposed.

 

Did you know your hair undergoes a complete transformation approximately every seven years? 

Toxins can persist in your hair for up to seven years. Consequently, daily choices, including exposure to coloring and perming agents, can damage the hair's cuticle, leading to brittleness, breakage, and premature aging.

 

We encourage you to choose hair colors with as few of these eight common chemicals as possible. Opting for a natural hair color can be a safer choice, and selecting an organic hair color made with pesticide-free ingredients offers even greater peace of mind. Be mindful to reduce potential chemical absorption through the scalp by choosing your hair color products carefully. Even switching to a safer hair color for every few applications can help minimize exposure to harmful chemicals.

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REFERENCES:

[1] Liu X, Grice JE, Lademann J, Otberg N, Trauer S, Patzelt A, Roberts MS. Hair follicles contribute significantly to penetration through human skin only at times soon after application as a solvent deposited solid in man. Br J Clin Pharmacol. 2011 Nov;72(5):768-74. doi: 10.1111/j.1365-2125.2011.04022.x. PMID: 21599723; PMCID: PMC3243011.

[2] Han JH, Lee HJ, Bang CH, Lee JH, Park YM, Lee JY. P-Phenylenediamine Hair Dye Allergy and Its Clinical Characteristics. Ann Dermatol. 2018 Jun;30(3):316-321. doi: 10.5021/ad.2018.30.3.316. Epub 2018 Apr 23. PMID: 29853746; PMCID: PMC5929949. 

[3] Malinauskyte E, Cornwell PA, Reay L, Shaw N, Petkov J. Effect of equilibrium pH on the structure and properties of bleach-damaged human hair fibers. Biopolymers. 2020 Nov;111(11):e23401. doi: 10.1002/bip.23401. Epub 2020 Sep 14. PMID: 32926408; PMCID: PMC7757171.

[4] Ali N, Marsh J, Godfrey S, Williams DR. Aqueous MEA and Ammonia Sorption-Induced Damage in Keratin Fibers. ACS Omega. 2018 Oct 31;3(10):14173-14180. doi: 10.1021/acsomega.8b01189. Epub 2018 Oct 25. PMID: 30411060; PMCID: PMC6217691.

[5] Scherrer MA, Rocha VB, Andrade AR. Contact dermatitis to methylisothiazolinone. An Bras Dermatol. 2015 Nov-Dec;90(6):912-4. doi: 10.1590/abd1806-4841.20153992. PMID: 26734880; PMCID: PMC4689087.

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    ammonia free hair colour
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  • Interesting article, thanks.

    Ronald Sohan on
  • It’s a great article about ammonia free hair colour Thank you

    Samar Kumar on

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