Wegmans has recalled its Food You Feel Good About Spring Water after tests confirmed some drinks contained bromate up to two-and-a-half times the level considered safe by the US Food and Drug Administration (FDA).
Long-term exposure to bromate may increase consumers' risk of cancer, according to the US government's Environmental Protection Agency. Concerns over its presence in water come several months after another cancer-causing substance, benzene, was discovered in batches of US soft drinks.
Wegmans had its bottled water brand tested after an independent lab claimed it found bromate levels in the drink at 27 and 28 parts per billion (ppb). The FDA maximum is 10ppb.
The retailer said its own results ranged from zero to 25ppb. "There is no imminent health risk to those who have consumed the product. However, it has been recalled and we encourage customers to return the product for a full refund," it said.
Wegmans found out about the independent lab tests from New York lawyer Ross Getman, the same man who first alerted the FDA to the continuing presence of benzene in some soft drinks.
"Wegmans has demonstrated how a responsible corporation acts in connection with consumer health," said Getman, calling for bottled water brands to be tested for bromate around the country.
Wegmans too said its rivals should be on their guard: "It does not affect other brands sold at Wegmans, but it does affect other brands produced by the same supplier for other retailers."
Bromate is formed in water when ozone and bromide ions react together. The chances of bromate in water are higher when ozone is used as a disinfectant for mineral water, and especially in the presence of calcium chloride, which is a bromide derivative.
Guidelines on how to avoid bromate in water have been published by the International Ozone Association.
Wegmans is not the first company to find unacceptable bromate levels in its mineral water. Perhaps the highest profile case was Coca-Cola, which in 2004 said its Dasani bottled water in Britain contained bromate above the country's 10ppb limit.
Coke eventually pulled Dasani out of the UK, although the move also came after the drink was criticised as re-processed tap water.