P-Phenylenediamine

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The correct title of this article is p-Phenylenediamine. The initial letter is shown capitalized due to technical restrictions.

Image:P-phenylenediamine.png

p-Phenylenediamine (PPD), also called 1,4-diaminobenzene or 1,4-phenylenediamine is an aromatic amine used as a component of engineering polymers and composites, aramid fibers, hair dyes, rubber chemicals, textile dyes and pigments. PPD is selected because of its low toxicity, high temperature stability, high strength, and chemical and electrical resistance.

Its CAS number is [106-50-3] [1] and its SMILES structure is Nc1ccc(N)cc1.

1 Uses
2 Contact allergen
3 Misconception
4 External links

[edit] Uses

This product is added to real henna or used alone to create black tattoo-like body art.

This compound is used in almost every hair dye on the market, regardless of brand. The darker the colour, usually, the higher the concentrations. Even the so-called "natural" and "herbal" hair colours, while ammonia-free, contain PPD. Some products sold as henna have PPD added, particularly "black henna". Using body art quality (BAQ) pure henna, or indigo is the only way to avoid PPD in hair dye.

[edit] Contact allergen

The CDC lists p-phenylenediamine as being known as one of many contact allergens. The NIOSH Pocket Guide to Chemical Hazards lists exposure routes as through inhalation, skin absorption, ingestion, skin and/or eye contact. It lists: throat irritation (pharynx and larynx), bronchial asthma, and sensitization dermatitis as symptoms of exposure. Sensitization is a life long issue, what may lead to active sensitization to black clothing, printer's ink, fax ink, hair dye, fur dye, leather dye, and photographic products among many other products.

One maker of this product states explicitly that it should not be used directly on the skin,^{[citation needed]} however, they admit other companies that produce may or may not warn the same.

[edit] Misconception

Some misinformation twists have led to PPD being described as a black mineral from the banks of the River Nile. This gives PPD an undeserved distinction as being both natural and exotic, which it is not.