"This contractor has a clear financial conflict of interest. It was absolute necessity for the panel to postpone this decision," said Jane Houlihan, Environmental Working Group's vice president for research.
She said the center also should prohibit Sciences International's involvement in the evaluation of any chemicals related to its industry clients and develop a conflict of interest policy for all contractors.
The environmental group said its review of government and company data showed that Sciences International was involved in risk evaluations for at least eight other chemicals produced by its clients.
Sciences International's clients have included BPA manufacturers Dow Chemical Co. and BASF.
Others clients include Union Carbide, Chevron, DuPont, 3-M, Syngenta, Amvac Chemical, ExxonMobil, the National Assn. of Manufacturers and the American Chemistry Council.
In a recent memo to the environmental group, Shelby said the center had no conflict of interest requirements for contractors but added "there are numerous steps in the process for developing expert panel reports that serve to minimize or eliminate any bias that might possible be introduced by the contractor."
Bisphenol A mimics the sex hormone estrogen, which can damage a developing reproductive system.
In newborn lab animals, studies have discovered that traces of the chemical -- similar to amounts that can leach from hard plastic infant and water bottles -- reduce sperm counts and cause genetic changes that are precursors of prostate cancer and breast cancer.
The plastics and chemical industries say the levels that leach from polycarbonate bottles are too low to be harmful, while more than 100 government-funded studies have found effects on lab animals at low doses.
Polycarbonate is an inflexible plastic used for infant bottles, multi-gallon water containers and refillable sports bottles.
BPA is also used to line cans of food and in some dental sealants.
marla.cone@latimes.com
