Hazardous Chemical Information System (HCIS)

o-Phenylenediamine

Carcinogen category notice: Category 3. Substances suspected of having carcinogenic potential are those substances which have possible carcinogenic effects on humans but in respect of which the available information is not adequate for making a satisfactory assessment. There is some evidence from appropriate animal or epidemiological studies, but this is insufficient to place the substance in Category 2.

Sensitiser notice: Some substances can cause a specific immune response in some people. Such substances are called sensitisers and the development of a specific immune response is termed `sensitisation'. Exposure to a sensitiser, once sensitisation has occurred, may manifest itself as a skin rash or inflammation or as an asthmatic condition, and in some individuals this reaction can be extremely severe. See Chapter 12: Guidance Note on the Interpretation of Exposure Standards for Atmospheric Contaminants in the Occupational Environment, published by Worksafe Australia.

No standard should be applied without reference to Guidance on the interpretation of Workplace exposure standards for airborne contaminants.

Note: This exposure standard is adopted from the ACGIH TLVs list. Readers should referto the relevant ACGIH documentation⁽¹⁾ for substantiation of this value. Moreover, after detailed review of therelevant literature, the Exposure Standards Working Group has recommended that o-phenylenediamine bedesignated as a sensitiser and classified as Carcinogen Category 3.

1. SENSITISATION

Shigemitsu et al, in an in vitro study ⁽²⁾ , found that lymphocytes from guinea pigs specifically sensitised to p-phenylenediamine exhibited cross-sensitivity with o-phenylenediamine. Allergic reactions have been evoked in a human patient by a 1% solution of either o- or p- phenylenediamine ⁽³⁾ . The Working Group is of the view that this data, together with analogy with other phenylenediamine isomers, is sufficient evidence to support the sensitiser notation for this substance.

2. CARCINOGENICITY

After reviewing the relevant data, the Working Group is also of the view that the evidence for carcinogenicity is such that o-phenylenediamine might be suspected of having carcinogenic potential based on animal bioassay and genotoxicity data.

3. RECOMMENDATION

The Working Group recommends that o-phenylenediamine be designated with a sensitiser notation. The reader is encouraged to review the section on Sensitisers in the Guidance Note on the Interpretation of Exposure Standards for Atmospheric Contaminants in the Occupational Environment for a more detailed discussion of senstisation.

The Working Group recommends that o-phenylenediamine be classified as Carcinogen Category 3 (substance suspected of having carcinogenic potential). The reader is encouraged to review the section on Carcinogens in the Guidance Note on the Interpretation of Exposure Standards for Atmospheric Contaminants in the Occupational Environment for guidance on the classification system of carcinogens.

1. ACGIH, Documentation of the Threshold Limit Values and Biological Exposure Indices, 6th ed, American Conference of Governmental Industrial Hygienists, Cincinnati, Ohio, 1991.

2. Shigemitsu, T., Ozawa, N. and Nakayama, H., 'In vitro study of the cross-sensitivity of hair dye using hapten-specific lymphocytes', Contact Dermatitis, 19, 30-35, 1988.

3. Reitamo, S et al, Allergic and toxic contact dermatitis: inflammatory cell subtypes in epicutaneous test reactions. British Journal of Dermatology, 105(5), 521-527, 1981.