Definition
ChEBI: A phenylenediamine in which the amino functions are at positions 1 and 4 of the benzene nucleus.
General Description
A white to purple crystalline solid (melting point 234 F) that turns purple to black in air. Flash point 309 F. Toxic by skin absorption, inhalation or ingestion. Used for production of aramid fiber, antioxidants, as a laboratory reagent, in photographic developing, and as a dye for hair and furs.
Reactivity Profile
P-PHENYLENEDIAMINE(106-50-3) is the stongest of the weak aromatic bases. P-PHENYLENEDIAMINE(106-50-3) neutralizes acids in weak exothermic reactions to form salts. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Reacts readily with oxidizing agents .
Air & Water Reactions
Oxidizes on exposure to air. The finely powdered base if suspended in air poses a significant dust explosion hazard. Soluble in water. Even as a solid will spot downwind areas purple/black (Roger Patrick, DuPont Engineer).
Potential Exposure
p-Phenylenediamine has been used in dyestuff manufacture, in hair dyes; in photographic developers; in synthetic fibers; polyurethanes, and as a monomer and in the manufacture of improved tire cords. Also used as a gasoline additive and in making antioxidants.
Fire Hazard
Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.
First aid
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. Give large quantities of water or a slurry of activated charcoal in water; and induce vomiting. Do not make an unconscious person vomit.
Shipping
UN1673 Phenylenediamines (o-, m-, p-), Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
Incompatibilities
Dust may form explosive mixture with air. A strong reducing agent. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides, acid chlorides; acid anhydrides; chloroformates, and strong bases. Incompatible with organic anhydrides; isocyanates, aldehydes. Heat and light contribute to instability. Keep away from metals.
Waste Disposal
Controlled incineration whereby oxides of nitrogen are removed from the effluent gas by scrubber, catalytic or thermal device.
Physical properties
White, red, or brown crystals. May darken on exposure to air.
Health Hazard
p-Phenylenediamine is a moderate to highlytoxic compound; the acute, subacute andchronic toxicity of this amine is greater thanthat of its ortho- and meta-isomers. The acutepoisoning effects in animals were manifestedby lacrimation, salivation, ataxia, tremor,lowering of body temperature, increasedpulse rate, and respiratory depression. Anintraperitoneal dose of 10.8 mg/kg (sus pended in propylene glycol) in male ratscaused the formation of methemoglobin tothe extent of 12.9% after 5 hours (Watan abe et al. 1976). The hydrochloride of thisamine has been reported to cause edemaof the head and neck in animals dosedwith 120–350 mg/kg. p-Phenylenediamine in hair dye formulations produced skinirritation and mild conjunctivial inflamma tion in a variety of test animals (Lloydet al. 1977). In guinea pigs, contact pro duced skin sensitization. Hair dyes con taining p-phenylenediamine damaged visionwhen applied into eyes. In addition, allergicasthma and inflammation of the respiratorytract resulted from exposure to higher con centrations. Reports in early literature citeseveral cases of human poisoning resultingfrom the use of hair dyes containingp-phenylenediamine. The toxic symptomsreported were liver and spleen enlargement,vertigo, gastritis, jaundice, atrophy of liver,allergic asthma, dermatitis, cornea ulcer,burning and redness in eyes, and presbyopia(the latter effects arising from using hair dyeson the eyebrows and eye lashes).
Tests for mutagenicity in Salmonellamicrosome assays (in vitro) were negative.With metabolic activation, upon oxidationwith hydrogen peroxide, most mutagenictests showed positive results. Tests forcarcinogenicity were negative, although itslightly increased the overall tumor ratein experimental animals. After oxidationwith hydrogen peroxide, the amine producedtumors in the mammary glands of female rats(Rojanapo et al. 1986).
Flammability and Explosibility
Nonflammable
Biochem/physiol Actions
p-Phenylenediamine causes allergic reactions with skin. It is widely used in hair dyes. It eventually forms Bandrowski′s base, which is found to be the primary cause for allergy. p-Phenylenediamine exposure results in dermatitis, urticaria and anaphylaxis. It acts as an electron donor and is known to reduce cytochrome c.
Carcinogenicity
A number of dermal carcinogenesis bioassays have been
reported using p-PDA alone in an organic solvent or in
combination with hydrogen peroxide. An 85-week study
in which female Swiss mice were treated with 5% or 10%
p-PDAin acetone, 0.02 mL/animal applied topically, showed
no evidence of carcinogenicity.
p-PDA was not found to be carcinogenic when administered
by diet to male and female F344 rats and B6C3F1 mice
at the dietary doses of 625 or 1250 ppm; the high dose
approximated the maximum tolerated dose. An
IARC Working Group concluded that on the basis of lack
of human data, and inadequate animal data, p-PDA was not
classifiable as to its carcinogenicity to humans. A
recent meta-analysis of 11 case-control studies and one
cohort study of the relationship between p-PDA exposure
through use of personal hair dye and bladder cancer did not
indicate any causal association.
Source
Bulk quantitities may contain m- and o-phenylenediamine and aniline as impurities.
Environmental Fate
Biological. In activated sludge, 3.8% mineralized to carbon dioxide after 5 d (Freitag et al.,
1985). In activated sludge inoculum, following a 20-d adaptation period, 80.0% COD removal was
achieved (Pitter, 1976).
Photolytic. A carbon dioxide yield of 53.7% was achieved when phenylenediamine (presumably
an isomeric mixture) adsorbed on silica gel was irradiated with light (λ >290 nm) for 17 h (Freitag
et al., 1985).
Chemical/Physical. p-Phenylenediamine will not hydrolyze because it does not contain a
hydrolyzable functional group (Kollig, 1993).
Purification Methods
Crystallise the diamine from EtOH or *benzene, and sublime it in vacuo; protect it from light. The acetate has m 304o. [Beilstein 13 IV 104.]
