18 January 1999 00:00 [Source: ICB Americas]A new animal study of bisphenol A, a key building block monomer for the manufacture of polycarbonate and epoxy resins, has failed to provide evidence of illnesses from low-dose exposures. This is the second major animal study within the past two months that has been unable to reproduce earlier claims of harm from low doses of the product.
In the latest study using rats, no evidence of treatment-related effects was found at any of the tested exposure levels. These included doses 10 times higher and 100 times lower than ones in the earlier study.
In October, a study of the potential dangers to mice from low-dose exposures of bisphenol A produced similar negative results. To date, none of the alleged harm to mice and rats from oral exposure to low doses of bisphenol A has been reproduced.
The new study, sponsored jointly by the Global Bisphenol A Industry Group of the society of the Plastics Industry (SPI) and the European Chemical Industry Council (CEFIC), was designed to investigate the potential effects on male reproductive organs from low-dose exposure to bisphenol A.
The experiment was designed to detect potentially permanent damage to male reproductive capacity caused by exposure during pregnancy and early life stages.
The SPI/CEFIC study found no effects on the male offspring of female rats exposed to Bisphenol A at 0.01, 0.1, 1 and 10 parts per million concentrations in drinking water. In addition, no adverse effects were observed for maternal toxicity or reproductive performance.
"The study did not reveal any estrogenic potential for bisphenol A when given orally at these low doses, neither did the study reveal any impairment of reproduction at the bisphenol A dose levels employed," says SPI/CEFIC.
According to the industry groups, the findings are consistent with the published literature on bisphenol A and support a traditional dose-response relationship between the test article and treatment-related effects.
The Japanese Chemical Industry Association says the new study, which was conducted in Tokyo, was "large and rigorous, studying several doses, and was conducted in accordance with internally recognized Good Laboratory Practices." In addition, officials say the results cast further doubt on the low-dose theory.
The findings were presented at the Kyoto Symposium on Endocrine Disrupters last month.
For the latest chemical news, data and analysis that directly impacts your business sign up for a free trial to ICIS news - the breaking online news service for the global chemical industry.
Get the facts and analysis behind the headlines from our market leading weekly magazine: sign up to a free trial to ICIS Chemical Business.
Asian Chemical Connections