PPD and Hair Colour Allergies

What is PPD?

One of the main causes of allergies to hair dye is a chemical known as para-phenylenediamine (or PPD). It is a dark dye used in almost every hair colour on the market, regardless of brand. The darker the colour, usually the higher the concentrations. More than two-thirds of hair dyes currently contain PPD or related chemicals. To obtain a dramatic colour change or to cover grey, this ingredient is unavoidable even in more “green” hair colour products, although lower concentrations can still be effective. PPD is a preferred chemical due to its ability to withstand high temperatures and retain its stability. As well as hair colour, it is used for dyes for fabrics, fur and dark makeup amongst other things. PPD causes mild to severe allergic reactions in many people. According to CBC news, rates of allergy to hair dye have jumped in several countries as more and people colour their hair. A recent survey in London found the frequency of positive reactions to PPD in patch tests doubled over six years to 7.1 per cent of adults who developed contact dermatitis after exposure. Due to conflicting studies done which have neither proven or disproven the toxicity of PPD, the Environmental Protection Agency has not classified it as a carcinogen. Therefore, no warnings of toxicity have been printed on boxes of hair dye.

Black Henna -a trigger to allergies?

One of the most dangerous applications of PPD is when it is added to henna, a natural dye. When used for temporary tattoos, henna laced with PPD is known as “Black Henna.” Although this is not an approved use for PPD in North America, some tattoo artists will illegally add the chemical to henna for darker temporary tattoos that dry faster than pure henna tattoos. Because the dye is applied while the PPD is in its oxidation process, its potential as an allergen is increased. Black Henna tattoos often result in a skin reaction similar to a chemical burn, which in turn results in a scar where the skin was tattooed. Once a person who has been exposed to PPD in black henna has an allergic reaction, they may suffer a lifelong sensitivity to the chemical. They will have future allergic reactions to hair colour and other things such as sunscreen, cosmetics and dark-coloured fabrics.

Why is it so bad?

When added to henna, the concentration of PPD is often much higher than what is approved for use in hair dyes, resulting in a minor to major allergic reaction. In black henna tattoos, the concentration of PPD has been shown to be as high as 15.7%, which is much stronger than in traditional hair dyes whose average is 3 – 6% (or in Organic Color Systems .03% to 0.6%). This henna stays on your skin for a few weeks until it fades. If the vendor tells you they are using ‘black henna’ — walk away! It takes one bad decision to ruin your life.

Product sensitivities

If sensitivities / allergies form as a result of ‘PPD‘ exposure, here are substances you may also react to:

  • PABA-based sunscreens or creams
  • Azo or disperse textile dyes
  • Sulfa drugs
  • Hair dyes
  • Black rubber products
  • Some “caine” drugs such as benzocaine
  • Sulfonamides
  • Para-aminosalicylic acid / sodium
  • Diaminodiphenylmethane (epoxy hardener)
  • Para-aminodiphenylamine (p-amino-diphenylamine)
  • Paratoluenediamine (p-toluenediamine)
  • 2,4-Diaminoanisole
  • Ortho-aminophenol (o-aminophenol)
  • Sulfones

To avoid and prevent allergic reactions:

  • Avoid black henna!
  • Use PPD free, natural vegetable based semi-permanent colours (not all are PPD free, so check first).
  • Use chemically-reduced permanent colours if you must have permanent colour done (for grey coverage or more dramatic colour change). When the concentration of PPD in a product is low enough, it can minimize or eliminate the reaction.
  • Always get a patch test done 24-48 hours before your colour service.
  • Always carry an antihistamine with you in case of a reaction.

Other Culprits? Of course, not all hair colour-related allergies are due to PPD’s, although it’s the most common. Other ingredients in permanent and semi permanent colours can also cause reactions…even natural ingredients. If you suffer from allergies, the key is to always get a patch test whenever you are using a new product. Plus, always use the most natural and chemically reduced options possible to lessen the allergic reaction. Click here to read about Organic Colour Systems which has the lowest PPD content possible in a permanent hair colour.