California’s Office of Environmental Health Hazard Assessment (OEHHA) announced that it has added CMNP (pyrazachlor) (CAS No. 6814-58-0) to the list of chemicals known to the state to cause cancer under Proposition 65.
The listing of CMNP (pyrazachlor) is based on its formal identification by the U.S. Environmental Protection Agency, an authoritative body, that the chemical compound is carcinogenic.
OEHHA is based its decision to list CMNP (pyrazachlor) as a carcinogen on a report published by the U.S. Environmental Protection Agency in 2011. The report, Cancer Assessment Document, Evaluation of the Carcinogenic Potential of CMNP (pyrazachlor) (US EPA, 2011a) identified the chemical substance as a carcinogen, OEHHA concluded.
In its Notice of Intent to List the chemical, OEHHA wrote, “US EPA concluded that CMNP is ‘Likely to be Carcinogenic to Humans’.
OEHHA is relying on U.S EPA’s discussion of data and conclusions in the report that CMNP (pyrazachlor) causes cancer. Evidence described in the report includes studies showing that CMNP increased the incidence of combined bronchiolar/alveolar carcinomas and adenomas in male mice, bronchiolar/alveolar carcinomas and combined carcinomas and adenomas in female mice, and renal tubule carcinomas and combined carcinomas and adenomas in male and female mice.”
OEHHA notes that the US EPA report (2011a) found that CMNP (pyrazachlor) causes increased incidence of combined malignant and benign lung tumors in male mice, malignant and combined malignant and benign lung tumors in female mice, and malignant and combined malignant and benign kidney tumors in both sexes of mice.
Pyrazachlor (CAS No. 6814-58-0) is not registered for use in the United States or the European Union. At one time the chemical was proposed for use as a growth regulator for various citrus crops.