Minnesota has become the first US state to ban the use of the controversial chemical bisphenol-A (BPA) in baby bottles. Concern focuses on the possible effects of BPA leaching into babies' feed when bottles are heated.
From the start of next year, manufacturers of sipper cups and baby bottles containing BPA cannot sell them in Minnesota, although retailers will still be able to sell existing stock until the beginning of 2011. BPA is used to make hard, clear plastics for food containers, dental sealants and the sealants that line food and beverage cans.
Although the new law treats BPA as a health threat, its supporters say scientists have not yet conclusively proved the link between the chemical and health problems.
Last year, the Food and Drug Administration ruled that BPA was safe and asked independent scientists to review its conclusion. After the report was criticised as flawed, FDA ordered a re-assessment. It continues to rate the chemical as safe despite independent research suggesting that the chemical mimics hormones such as estrogen and could be linked to other serious health problems.
Similar bans on the use of BPA in baby bottles are under consideration in California, New York and Connecticut. Also a nationwide ban has been proposed to Congress.
Meanwhile, a Chicago City Council advisory panel has given preliminary approval earlier this week to a proposal to ban the sale of baby bottles containing BPA.
The ban would apply to empty food or drink containers intended for use by children under three years of age.
Chemical industry representatives at the hearing disputed the link between BPA and medical problems.
In March, six baby bottle manufacturers confirmed their intention to stop using BPA in their bottles sold in the US but will continue to sell the bottles in the UK. The UK Food Standards Agency insists BPA in UK plastic products is "well below the levels considered harmful".
Major retailers and manufacturers, such as Wal-Mart and Toys R Us, have promised to phase out the use of BPA in children's products.
Last autumn, Canada became the first country in the world to ban the import and sale of polycarbonate baby bottles containing BPA. The government also pledged to spend $1.7m over three years to study the chemical.
Last year federal health minister Tony Clement said: “We have concluded that early development is sensitive to the effects of bisphenol A. Although our science tells us that exposure levels to newborns and infants are below levels that cause effects, we believe the current safety margin needs to be higher."
The chemical industry claims that BPA is one of the most extensively-tested chemicals, and that in Europe, new EU legislation will ensure its safety.
Steve Elliot, chief executive of the Chemical Industries Association, said: "There's been lots of work done, whether it's been by the Food and Drug Administration in the States, whether it's by the Food Standards Authority at a European level or the FSA in the UK. Lots of data, lots of research, lots of sampling and none of those tests suggest that there is a risk to human health."