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P-phenylenediamine chemical graphicWhat Is It?

To achieve a permanent color, many hair dyes work using a system of ammonia (or ethanolamines in the case of some ammonia-free products), hydrogen peroxide, and p-phenylenediamine. The ammonia pulls apart layers of the hair’s proteins, so that the dye can access the hair shaft. Next, hydrogen peroxide bleaches the hair and helps p-phenylenediamine, one of the primary coloring agents to become trapped in hair.

P-phenylenediamine, PPD, is one of many coal-tar colors, which are derived from petroleum. Unlike most color additives, coal-tar dyes are exempt from needing FDA approval, despite the numerous health effects associated with coal-tar dyes.

The Health Concern

Short-term exposure of PPD can result in skin and eye irritation, and asthma – and more serious impacts like vertigo, convulsions, and coma.

P-phenylenediamine has demonstrated some endocrine-disrupting capabilities. In one laboratory study, rats exposed to levels of PPD congruent with those in hair dye exhibited sexual health impacts associated with reproductive toxicity. More study is needed to understand PPD’s endocrine-disrupting abilities.

PPD is a strong potential skin sensitizer. Skin sensitizers are substances that pave the way for a future allergic response. As opposed to just skin irritation, skin sensitization is actually an immune response where the body builds up a “memory” of the substances upon first contact. When someone is exposed a second time, it can lead to an allergic response.

As mentioned above, PPD is often mixed with hydrogen peroxide in hair color systems. When the two mix together, they can form a substance called Bandrowski’s base. This substance has exhibited mutagenic properties – the ability to alter genetic material, which can cause cancer. 

PPD may be a neurotoxin. More research is necessary to determine its potential impacts.

Finally, PPD is very toxic to aquatic life. Considering toxicity to aquatic life is more important than ever as the health of our oceans and waterways become increasingly compromised.

How to Avoid It
  • Make the swap to a MADE SAFE certified hair color or color restoration product. MADE SAFE does not allow PPD as well as numerous other toxic ingredients.
  • Look for and avoid p-phenylenediamine on hair color labels. It can also be listed as para-phenylenediamine, 4-aminoaniline, p-diaminobenzene, 1,4-benzediamine, and 1,4-phenyl diamine.
  • If you get your hair professionally colored, ask your hairdresser to see the hair dye’s list of ingredients. If the product contains PPD, ask if there are healthier alternatives.
  • If you like the look of professional color, but want to skip out on the toxic ingredients found in most conventional dyes, bring your own color to the salon. That way, you’ll get professional precision, without the toxic exposure.
  • Remember that hair dyes can contain other toxic substances besides PPD. And double check the ingredients of products that are labeled as “natural” and organic.” Some of them still contain PPD, and other toxic ingredients.
  • If you’re not ready to make the change to a MADE SAFE certified product, when applying your conventional dye, make sure to use nitrile gloves, apply in a well-ventilated area, and follow the directions carefully.
  • If you are a hairdresser, because you likely handle hair color often, you are at more risk of exposure to PPD and other toxic ingredients than the general public. Make sure to protect yourself during color sessions with proper gloves and proper ventilation. Get to know what’s in the products you use and consider making healthier swaps where you can. For more tips on how to protect yourself in the salon, check out this resource from Women’s Voices for the Earth.
  • Ditch the dye completely! An increasing number of celebrities are going grey or intentionally dying their hair silver to get the grey look. Need guidance in your journey to go grey? Read True Roots: What Quitting Hair Dye Taught Me About Health and Beauty by Ronnie Citron-Fink.
  • Reduce your overall exposure to harmful ingredients by choosing MADE SAFE certified personal care.