NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Butyl Benzyl Phthalate (BBP).

The National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for butyl benzyl phthalate (BBP) to cause adverse effects on reproduction and development in humans. BBP is one of 7 phthalate chemicals evaluated by the NTP CERHR Phthalates Expert Panel. These phthalates were selected for evaluation because of high production volume, extent of human exposures, use in children's products, and/or published evidence of reproductive or developmental toxicity. BBP is used in the production of vinyl tiles and polyvinyl chloride (PVC) to make products such as food conveyor belts, carpet tile, tarps, artificial leather, automotive trim, and traffic cones. The results of this evaluation on BBP are published in a NTP-CERHR monograph which includes: 1) the NTP Brief, 2) the Expert Panel Report on the Reproductive and Developmental Toxicity of Butyl Benzyl Phthalate, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to BBP on human development and reproduction. First, the NTP concludes there is negligible concern for adverse reproductive effects in exposed men. Data are insufficient to reach a conclusion on possible eproductive effects in exposed women. There is no direct evidence that exposure of people to BBP adversely affects reproduction or development, but studies reviewed by the expert panel show that oral exposure of laboratory animals to high doses (>/=1000 mg/kg body weight/day) of BBP can adversely affect development, including development of the male reproductive tract. Second, the NTP concludes that there is minimal concern for developmental effects in fetuses and children. Evidence showed adverse reproductive effects in rats at doses of 100 mg/kg body weight/day, but not at 20 mg/kg/day. Exposure estimates for women of reproductive age were estimated to be 7.8 mug/kg body weight/day. Therefore, this estimated exposure is at least 2,500-to 25,000- fold lower than the toxic dose in rats. NTP-CERHR monographs are transmitted to federal and state agencies, interested parties, and the public and are available in electronic PDF format on the CERHR web site (http://cerhr.niehs.nih.gov) and in printed text or CD-ROM from the CERHR (National Institute of Environmental Health Sciences, P.O. Box 12233, MD EC-32, Research Triangle Park, NC; fax: 919-316-4511).