Scientists studying the growth of human prostate cells in mice found that feeding the animals the chemical bisphenol A (BPA) almost tripled their risk of cancer or pre-cancerous changes.
The doses of BPA given to the mice were relatively the same as those commonly seen in pregnant women.
BPA is widely used to soften plastics, but there have been serious concerns about its ability to mimic the hormone oestrogen. The chemical is now banned from babies' feeding bottles in the European Union.
Professor Gail Prins, from the University of Illinois at Chicago, who led the new research, said BPA was "very hard to avoid" despite the fact that it has been linked to several types of cancer in laboratory animals.
The study, published online in the journal Endocrinology, involved implanting prostate stem cells taken from deceased young adult men into male mice. Prostate stem cells arise during early foetal development and maintain a man's prostate tissue throughout his life.
They fed the mice the chemical for two weeks as the implanted stem cells transformed into adult prostate tissue.
They found that a third of the mice samples contained either pre-cancerous changes, or full-blown tumours, compared with just 12% of mice who were fed harmless oil instead.
If the stem cells were exposed to BPA twice, before implantation and again as they developed in the mice, they produced pre-cancerous abnormalities or cancer in 45% of the tissue samples.