Draft: Evidence on the carcinogenicity of 4-amino-2-nitrophenol

PREFACE The Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65, California Health and Safety Code 25249.5 et seq.) requires that the Governor cause to be published a list of those chemicals " known to the state " to cause cancer or reproductive toxicity. The Act specifies that " a chemical is known to the state to cause cancer or reproductive toxicity...if in the opinion of the state's qualified experts the chemical has been clearly shown through scientifically valid testing according to generally accepted principles to cause cancer or reproductive toxicity. " The lead agency for implementing Proposition 65 is the Office of Environmental Health Hazard Assessment of the California Environmental Protection Agency. The " state's qualified experts " regarding findings of carcinogenicity are identified as the members of the Carcinogen Identification Committee of the OEHHA Science Advisory Board (22 CCR 12301). 4-Amino-2-nitrophenol was assigned a final priority of 'high' carcinogenicity concern and placed on the Final Candidate list of chemicals for Committee review on June 12, 1998. A public request for information relevant to the assessment of the evidence on the carcinogenicity of this chemical was announced in the This draft document Evidence on the Carcinogenicity of 4-Amino-2-nitrophenol was developed to provide the Committee with relevant information for use in its deliberations. It reviews the available scientific evidence on the carcinogenic potential of 4-amino-2-nitrophenol. A public meeting of the Committee to discuss this evidence is scheduled for December 1998. The exact meeting date will be published in the California Regulatory Notice Register. Written public comment on the document should be submitted to OEHHA by November 24, 1998, in order to be considered by the Committee in advance of the meeting. During the December meeting, the public will have an opportunity to present verbal comments to the Committee. Table 2: Lung tumors in male and female strain A/St mice treated with 4-amino-4-Amino-2-nitrophenol (C 6 H 6 N 2 O 3) has been used as an oxidation base in formulations of hair dyes. Technical grade 4-amino-2-nitrophenol induced tumors of the urinary bladder in male rats, and there is some evidence for a similar effect among female rats. Tumors of the urinary bladder are extremely rare among untreated rats. Preparations of 4-amino-2-nitrophenol have also demonstrated genotoxic potential in a number of short-term tests in bacterial and mammalian cells, in vitro and in vivo. There is some evidence that a purified …