Paraphenylenediamine Chemical formula

Chemical information

Parafenilendiamina. p-Phenylenediamine; 1,4-Benzenediamine.
Chemical formula: C6H4(NH2)2 = 108.1.
CAS — 106-50-3.
NOTE. Commonly known in the hairdressing trade as ‘para’. ‘PPD’ is an abbreviation sometimes used for paraphenylenediamine, which should not be confused with tuberculin purified protein derivative, which is also referred to by the same abbreviation.


Paraphenylenediamine is widely used in permanent hair colour preparations. However it is a potent contact allergen and EU legislation restricts its concentration in the finished product to a maximum of 6% calculated as free base. Both type I and type II reactions occur and symptoms usually present as dermatitis on the face or hands. More severe reactions can lead to angioedema; anaphylaxis has also been reported. Systemic symptoms similar to those after ingestion (see below) may also occur following absorption through intact skin. For references to hypersensitivity after skin tattoos with henna that was adulterated with paraphenylenediamine. Application of tints to the eyelashes or eyebrows may produce blepharoconjunctivitis, eye oedema, and eye pain, with progression to facial oedema and dermatitis, lachrymation, photophobia, uveitis, and keratitis in severe cases. Corneal necrosis has led to blindness. In some countries, use of paraphenylenediamine in eyelash or eyebrow tints is not permitted. Early symptoms after ingestion of paraphenylenediamine are vomiting and abdominal pain. Severe oedema of the face and oropharynx can lead to life-threatening obstruction of the airways. Other symptoms may include hypotension or hypertension, tachycardia, hepatotoxicity, renal failure, metabolic acidosis, methaemoglobinaemia, rhabdomyolysis, tremor, convulsions, and coma; multisystem failure may be fatal. Some studies have linked hair dyes with mutagenicity and carcinogenicity, although such findings have often been refuted. In Europe, EU legislation carefully controls which substances may be safely used in hair dye products. Paraphenylenediamine is also used in the textile and photographic industries.

Adverse effects.

1. Ashraf W, et al. Systemic paraphenylenediamine (PPD) poisoning: a case report and review. Hum Exp Toxicol 1994; 13: 167–70
2. Lifshits M, et al. Fatal paraphenylenediamine (hair dye) intoxication in a child resembling Ludwig’s angina. J Toxicol Clin Toxicol 1993; 31: 653–6
3. Anuradha S, et al. Acute renal failure following para-phenylenediamine (PPD) poisoning: a case report and review. Ren Fail 2004; 26: 329–32
4. Kallel H, et al. Clinical manifestations of systemic paraphenylene diamine intoxication. J Nephrol 2005; 18: 308–11
5. Sosted H, et al. Severe allergic hair dye reactions in 8 children. Contact Dermatitis 2006; 54: 87–91
6. Brahmi N, et al. Acute myocarditis and myocardial infarction induced by paraphenylenediamine poisoning. Interest of angiocoronarography. Int J Cardiol 2006; 113: E93–E95
7. Teixeira M, et al. Contact allergy to para-phenylenediamine in a permanent eyelash dye. Contact Dermatitis 2006; 55: 92–4
8. Patel S, et al. Patch test frequency to p-phenylenediamine: follow up over the last 6 years. Contact Dermatitis 2007; 56: 35–7.
Published May 08, 2019.