In an important U-turn, America has also promised that in future it will not lobby on behalf of its manufacturers if European countries reconsider cutting the use of products containing the chemicals, called phthalates.
Though the US is not stopping the use of the chemicals, five European countries and Canada have now moved to ban or cut their use in toys, citing scientific studies that suggest they might affect human development.
In a letter to two members of the US House of Representatives, the vice- president, Al Gore, has pledged funds from the powerful Environmental Protection Agency (EPA) and the US Department of Health to "step up their own efforts on risk assessment and toxicology related to phthalates...with particular attention to potential cancer and endocrine effects of phthalates."
The move is a total reverse of the US government's position last year, when it lobbied fiercely on behalf of American toy manufacturers as the European Commission considered imposing a ban on the use of a number of phthalates in toys. Ten of the 20 commissioners voted in favour of the ban last July - one short of the majority required to impose a ban.
Since then European scientists have produced new data, suggesting that the chemicals can leak out of the toys, while separate animal studies have pointed to effects such as cancers and shrunken testicles.
The chemicals are principally used in toys to soften otherwise brittle plastics. But environmental groups and new scientific studies have suggested that when children suck the toys - a common practice - the phthalates can be ingested.
Professor James Bridges, who heads a committee of scientists advising the EC on toxicity, told The Independent: "There is sufficient uncertainty about the effects that we should take precautions."
The British Plastic Federation, which represents British manufacturers, says in a letter today that neither of the two softeners studied, called DINP and DEHP, has been shown to be carcinogenic to humans.
Review, page 2Reuse content