para phenylene diamine(PPD)

Chemical Name: Para-phenylenediamine

CAS Number: 106-50-3

Molecular Formula: C6H4(NH2)2

Molecular Weight: 108.16 g/mol

Synonyms: PPD, 1,4-Benzenediamine, p-phenylenediamine

Appearance: PPD is slightly reddish-brown.

Odor: It may have a faint, characteristic odor.

Solubility:Soluble in water and alcohol, particularly in acidic or basic conditions.Slightly soluble in ether.

Melting Point: 168–170°C (334.4–338°F)

Boiling Point: 300°C (572°F)

Density: 1.23 g/cm³

Maximum Usage Concentration: As discussed, PPD is used in hair dyes at concentrations ranging from 2% to 5%, with most regulations capping it at 2.5% in finished products (higher concentrations may be used in certain formulations for professional or specialty use).

Skin Sensitivity and Allergies: PPD can cause allergic reactions, including contact dermatitis, in sensitive individuals. Therefore, it is critical to conduct a patch test 48 hours before using any hair dye product containing PPD.

Irritation: PPD can be an irritant to the skin, eyes, and respiratory tract, particularly when in concentrated forms.

preparation of hair dyes

1.Effective and Long-lasting Color

2.Uniform Coverage

3.Gray Coverage



Usage- In most permanent hair dye products, PPD is used at 2% to 5%. This concentration is effective for providing vibrant, long-lasting color and covering gray hair.