2,5-Diaminotoluene

Description

p-Toluylenediamine is a hair dye associated with contact dermatitis in hairdressers. Cross reactivity is observed with PPD.

Chemical properties

Colorless plates. Soluble in water, ethanol, ether, and hot benzene 2,5-Toluenediamine is used in hair and fur dyes.

The Uses of 2,5-Diaminotoluene

2,5-Toluenediamine is used primarily in hair dye formulations as one of the major oxidation dye precursors. It is also used in the synthesis of saframine, a family of dyes used as biological stain, and may be present in indelible ink, antifreeze, and nail polish.
As may be expected from its use in hair dye formulations, hairdressers and barbers may be exposed to 2,5-TDA. Workers in the dye manufacturing industry may also be exposed.

Definition

ChEBI: A diamine in which the two amino groups are substituted into toluene at the 2- and 5-positions.

Synthesis Reference(s)

Journal of the American Chemical Society, 102, p. 6182, 1980 DOI: 10.1021/ja00539a054

Flammability and Explosibility

Non flammable

Contact allergens

Toluene-2,5-diamine is a permanent hair dye involved in contact dermatitis in hairdressers and consumers. It does not cross-react with PPD, but cosensitization is frequent.

Safety Profile

Poison by ingestion and subcutaneous routes. A skin irritant. Mutation data reported. Questionable carcinogen. Has a toxic action upon the liver and can cause fatty degeneration of that organ. Its total effect upon the body seems to take place three chfferent ways. It is toxic to the central nervous system, producing jaundice by action on the liver and spleen, and anemia by destruction of the red blood cells. This action is quite similar to that of aniline, although by no means identical with it. Its high boiling point and the fact that the material is solid at room temperature make it somewhat less hazardous than aniline, particularly at ordinary working temperatures. The literature contains a reference to a permanent injury to an eye due to the use of this material as an eyelash dye. It is considered to be an irritating dye material. When heated to decomposition it emits toxic fumes of NOx. See also other toluene diamine entries and AROMATIC AMINES.

Carcinogenicity

The possible carcinogenicity of 2,5-TDA (as sulfate salt [6369-59-1]) was tested by the National Cancer Institute in a dietary feeding study. Groups of 50 male and female F344 rats (600 or 2000 ppm) and B6C3F1 mice (600 or 1000 ppm) were given diets containing 2,5-TDA for 78 weeks and then observed for an additional period of 28–31 weeks for rats and 16–19 weeks for mice. The only statistically significant increased incidence was in lung tumors in high-dose female mice, but the evidence was not convincing enough to be attributed to 2,5-TDA. Overall, the compound was considered noncarcinogenic.