Powerful and Comprehensive Study Counters Low Dose Claim; New Study Finds No Reproductive Risks From BPA
Arlington, VA - One of the largest, most comprehensive and most definitive reproductive toxicology studies related to polycarbonate plastic has found no evidence that the component bisphenol A (BPA) has long-term effects on reproductive health. Polycarbonate is used in a variety of food contact applications, ranging from baby bottles to water cooler bottles and food storage containers. BPA is used in making polycarbonate, as well as epoxy resins.

RTI conducted the study for the Society of the Plastics Industry, Inc., a trade group. The study used laboratory rats to examine a range of BPA doses in the diet, from extremely low to extremely high.

The results were presented at the Low-Dose Peer Review Workshop conducted by the National Toxicology Program of the National Institute of Environmental Health Sciences in October 2000. The NTP Biostatistics and Modeling Subpanel called this study "arguably the most comprehensive of the studies we evaluated."

Update: The U.S. EPA and its German counterpart subjected the RTI study to the first and, as of September 2003, the only international regulatory audit and reported "no findings" of fault in any aspect of the study. (EPA Notice of Inspection ID A940001, report of site visit Jan 30-Feb 1, 2001, available from www.epa.gov/foia/.)

BPA is an essential building block for making polycarbonate plastics, as well as for making epoxy resins used in coatings. The low-dose issue became important after two different research findings were connected. First, research showed that while BPA generally does not leach from plastics and epoxies, if it does leach, it does so at extremely low levels. Second, small toxicology studies raised questions about reproductive effects of low doses, leading to a series of larger studies designed to fully explore the questions.

The RTI study is the latest in a series of studies conducted by five different independent research entities - including a reproductive health study conducted by the Japanese government - all of which found no reproductive health risks from BPA. Because of the consistent findings in these studies, the NTP Bisphenol A Subpanel was "not persuaded that a low dose effect of bisphenol A has been conclusively established as a general or reproducible finding."

RTI study director Dr. Rochelle W. Tyl, an internationally respected reproductive toxicologist, described it as "the most definitive study conducted to date on possible effects of both low and high doses on endocrine-sensitive endpoints." The study examined more than one million data points from three generations of laboratory rats exposed to BPA over a wide range of doses. Results showed no indication of any "low-dose" effect in any generation.

Toxicologist Dr. James Lamb, formerly with the National Institute of Environmental Health Sciences and a member of the National Research Council expert panel on endocrine disruption, said it was significant that the three-generation study looked for effects of a range of exposures at all stages of development. "The concerns raised by sketchy or incomplete data have now been conclusively addressed," he said, "The results indicate very clearly that there is no risk to human health from these low-dose exposures."

The RTI study met and surpassed the highest international standards for reproductive health testing, and included independent oversight of methodology and data collection. It was sponsored by the Bisphenol A Study Group, which is part of the Society of the Plastics Industry, Inc. Results already have been presented at two international scientific conferences, and will be submitted for publication in a peer-reviewed professional journal. Interested individuals can also find more information about the study on the bisphenol A website at www.bisphenol-a.org.

Founded in 1937, the Society of the Plastics Industry, Inc. is the trade association representing the fourth-largest manufacturing industry in the United States. SPI's 1,700 members represent the entire plastics industry supply chain, including processors, machinery and equipment manufacturers and raw material suppliers. The U.S. plastics industry employs 1.5 million workers and provides $304 billion in annual shipments.

The American Plastics Council is a national trade association representing 24 of the nation's largest resin producers, including monomer and polymer production and distribution. Founded in 1988, APC works to make plastics a preferred material by demonstrating they are a responsible choice in a more environmentally conscious world. Additional information on APC can be found at www.plastics.org.

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Technical Summary Specifically, the RTI study found:

No significant changes in prostate or other reproductive organ weights in any of the three generations of laboratory rats tested at any dose level;
No effects on daily sperm production or efficiency of sperm production in any generation at any dose level;
No significant changes in markers of sexual maturity below the highest dose tested;
No health-related effects below the two highest dose levels, consistent with other research used to assess the safety of bisphenol A;
A normal monotonic dose-response pattern was seen in all generations and no treatment- or dose-related effects were observed in any generation at any dose below 5 mg/kg/day; and
This study does not support previous, small studies that had suggested effects in the low-dose region, at "environmentally relevant" concentrations.
Conducted at the Research Triangle Institute, Research Triangle Park, NC, under Good Laboratory Practices, the study met or exceeded current international standards. The study explored key indicators of possible reproductive toxicity to parents and offspring at all stages of development through three generations in 30 females and males per group. The study used seven dietary concentrations ranging from 0.015ppm to 7500ppm (providing BPA doses ranging from ~0.001 to 500 mg/kg/day) with 30 males and females per dose group per generation.