Copper poisoning from vending machines

S EVERAL health departmenits lhave reported cases of illness that appear to be copper poisoning associated with carbonated drinks obtained from vending machines. These machines, the post-mix type, release 1 ounce of a flavored syrup into a cup and then add 5 or more ounces of carbonated water. In the reported instances of alleged poisoning, the individuals who became ill developed symptoms generally described as acute gastric upset about 12 hours after tlhe vending machine had been in use. The cases of poisioning seemed to occur only after a faulty check valve allowed carbon dioxide to flow into a copper waterline connecting the machine to the building's water supply. Whlere there is a f aulty cheek valve, the carbon dioxide usually flows back into the water supply because the gas pressure in the tank is greater than the pressur-e in the building's waterline. Our investigation at the University of Indiana was conducted to (letermine wvhether copper poisoninlg couild resuilt from a carbonated beverage dispen-sed from a post-mix machine that uses a copper waterline.