On Friday, attorneys general from Connecticut, New Jersey and Delaware sent letters to a number of eleven companies that produce baby bottles, urging them to stop using bisphenol A (BPA) in formula containers.

The chemical has raised much concern over the past few months, since several studies have indicated that it might be harmful to humans, who can come to ingest BPA that leaks into water and food.

At the beginning of September, researchers at the Yale School of Medicine revealed that bisphenol A could cause developmental problems in infants’ brains and hormonal systems, thus prompting several United States retailers to decide to drop BPA products within the following year.

Even though the Federal Drug Administration (FDA) has issued a report informing that the chemical was safe for use in food packaging and bottles, it seems that the preliminary study that was conducted last month, showing there might be a connection between BPA and increased risk of heart disease and diabetes, has rekindled the controversy.

The attorneys general sent their letters to manufacturers Avent America Incorporated, Disney First Years, Gerber, Handicraft Company, Playtex Products Incorporated and Evenflo Company, as well as to baby formula producers Abbott, Mead Johnson, PBM Products, Nature's One and Wyeth.

BPA provides shatterproof quality to polycarbonate plastic and is found in various products such as water bottles, eyeglass lenses, compact discs and some medical devices.

The FDA has announced that they would further look into the matter and has also advised people to avoid warming up food in plastic containers, since heating the latter might cause them to leak the chemical.