Anthraquinone is an organic compound whose structure serves as a basic building block for a number of naturally occurring plant pigments. The compound is used in the production of dyes and as a catalyst for the production of wood pulp. Anthraquinone is also an effective goose repellent – the birds experience an unpleasant intestinal reaction after eating grass that is treated with the compound.
Two-year toxicity tests conducted by the National Toxicology Program have raised serious concerns about the safety of anthraquinone. According to the NTP report on anthraquinone released in February 2004, the test results showed clear evidence of liver carcinogenicity in laboratory animals that consumed feed containing the compound. The researchers also found evidence of non-cancerous lesions in other organs, along with possible effects on the endocrine system. Full report (http://ntp.niehs.nih.gov/go/14836).
In September 2007, the California Environmental Protection Agency added anthraquinone to the list of chemicals known to cause cancer. The public listing of known cancer-causing agents is required by the Safe Drinking Water and Toxic Enforcement Act, commonly known as Proposition 65.1 The agency based its listing on the National Toxicology Program’s formal identification of anthraquinone as a carcinogen in laboratory animals.
Back in 1998, the compound was approved by the U.S. Environmental Protection Agency for use as a non-lethal goose repellent in terrestrial areas near airports, commercial and industrial sites, and developed urban areas.2 The EPA conducted a review of anthraquinone following a request by Environmental Biocontrol International to approve the use of the compound. Based on studies submitted by the company, the U.S. EPA concluded that the overall toxicological risk to humans from exposure to anthraquinone was considered negligible. For more information on the findings and conclusions of the EPA review, please see the Anthraquinone Fact Sheet (http://www.epa.gov/pesticides/biopesticides/ingredients/factsheets/factsheet_122701.htm) .