p-Phenylenediamine

Other names: PPD, p-Phenylenediamine, 1,4-phenylenediamine, benzene-1,4-diamine, para-phenylenediamine, Paraphenylenediamine

Harm score: 4 (Slightly harmful chemistry)

Paraphenylenediamine, also known by the names p-Phenylenediamine, PPD, p-phenylenediamine, 1,4-phenylenediamine, benzene-1,4-diamine, is an organic compound characterized by the presence of two amine groups (-NH2). Under normal conditions, this chemical compound takes the form of white to slightly pinkish crystals which dissolve readily in alcohol, ether and hot water. With the chemical formula C6H8N2 it belongs to the group of aromatic amines. Interestingly, p-Phenylenediamine can exist in two isomers, which are referred to in the literature as ortho- and meta-phenylenediamine.

Paraphenylenediamine is widely used in industry, especially in cosmetics and textiles. A very common use is its presence in hair dyes. Due to its ability to react with hydrogen peroxide, this substance can produce a wide range of shades. In addition, p-Phenylenediamine is also used for the production of polyurethane foams, for the manufacture of rubber, as well as in various plant fertilisers. Furthermore, it also serves as an intermediate in the production of some pharmaceuticals and is a component of some printer inks. It is important to note that caution should be exercised when handling paraphenylenediamine, as it is considered an allergenic compound and can cause sensitisation with prolonged or repeated contact.