04 June 2001 00:00 [Source: ICB Americas]The American Chemistry Council (ACC) says it does not believe a scientific panel's findings about the low-dose effects of certain hormone-like chemicals warrants a change in pre-market test procedures.
A National Toxicology Program (NTP) report recommends that the Environmental Protection Agency (EPA) should consider rewriting the guidelines that the industry must follow in conducting regulatory tests of their products prior to agency approval.
A scientific panel said the agency should "revisit" the testing guidelines it has developed to determine whether changes are needed to ensure the tests detect hormonal effects of certain chemicals that may occur at very low levels, well below the "no effects" levels determined by traditional testing.
The panel also said the chemicals, called endocrine disruptors, deserve greater scrutiny and additional research.
"Based on a preliminary assessment of the NTP report, the council does not believe that the report warrants a change in the chemical evaluation process," the ACC said in a statement.
After a more thorough examination, the industry group said it would consider the report's call for additional research on the low-dose hypothesis.
"Importantly, there must be a clear framework for evaluating new and existing information in a weight-of-the-evidence context. Without this framework, it is unclear how additional research could contribute to resolution of the low-dose hypothesis," ACC said.
At the request of the EPA, the NTP convened a peer-review panel in October 2000 to evaluate the scientific evidence about low-dose effects of hormone-like chemicals. The NTP report was released for comment on May 14.
If a low-dose phenomenon were scientifically proven in general for hormonally active substances, the standard approach for setting dose levels for toxicity testing would need to be reexamined throughout many EPA programs.
The panel recommended that additional multi-generational studies might use a range of different dosages to better determine if any reproductive problems result in the offspring or grand-offspring of exposed animals. The scientist also suggested to the EPA that it consider the best strains and ages of rodents for such tests.
Under current regulations, studies are undertaken at three or four levels--where each dose may be two- to four-fold less than the other. The highest dose at which no effect on the animal is seen is considered the "no effect" level.
But the panel said the raw data suggested that at even lower levels, an effect might occur, so that the traditional study may need to be rethought.
Meanwhile, the American Plastics Council (APC) says it is pleased that the conclusions of the independent panel of scientific experts "further supports the safety of consumer products made from bisphenol-A (BPA)."
The peer review panel established by the NTP recommended additional research on how exposure to BPA at low level doses affects test animals.
But the "overwhelming weight" of scientific evidence reviewed by the NTP panel shows that there is "no basis for health concerns from exposure to low doses of BPA," said Steven Hentges, executive director of the APC's polycarbonate unit.
"Consumers can continue to choose polycarbonate and epoxy products with confidence in their safe use," said Dr. Hentges.
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