RENEE MONTAGNE, HOST:
The makers of soft drinks are under pressure to replace an additive they've used for a long time, to give colas their brown coloring. NPR's Allison Aubrey reports consumer advocates have raised concerns about the safety of that additive. And now, manufacturers have come up with a solution they hope will put the issue to rest.
ALLISON AUBREY, BYLINE: Around the corner from Studio 3A, here in the NPR newsroom, a cubby of vending machines draws traffic 24 hours a day.
(SOUNDBITE OF VENDING MACHINE)
MARIA GODOY: I need a drink, so there we go.
AUBREY: Senior editor Maria Godoy pops open a can of Coke Zero.
(SOUNDBITE OF CAN OPENING, LAUGHTER)
AUBREY: Coke is popular here. And the way this bubbly drink gets its brown color is from a type of caramel coloring. Consumer advocate Michael Jacobson, of the Center for Science in the Public Interest, says a chemical in the coloring is shown to cause cancer in rodents. He says it's nothing like the caramel we'd make in our own kitchen.
MICHAEL JACOBSON: It starts with sugar that's treated with ammonia under high temperatures, and that's what leads to the carcinogens. And we don't think that this should be used in the food supply.
AUBREY: Now, the Food and Drug Administration says we'd have to drink something like a thousand cans of soda a day to reach the doses that appear to cause cancer in rodents.
But nonetheless, last year the state of California placed the chemical - known as 4-MI - that's found in the coloring on a list of cancer-causing agents, and told soda-makers that if they didn't get most of it out of their products, they'd be required to print a cancer warning message on every can - a decision the soda industry says was ridiculous.
TED NIXON: Caramel color is now, has always been, safe and harmless.
AUBREY: That's Ted Nixon. He is CEO of the world's largest manufacturer of caramel coloring. Coca-Cola is one of his clients. When California regulators made it clear that they saw the 4-MI in caramel as a problem, he says his scientists went back to the drawing board.
NIXON: We did have to change these various inputs of temperature, pressure, and the various ingredients that we're using in order to change this one attribute.
AUBREY: So starting a few months ago in California, with no fanfare, Coca-Cola and other soda makers made the switch to this newly modified caramel coloring. Coke plans to use it nationally going forward, though they say the 4-MI in their product never posed a health or safety risk.
Allison Aubrey, NPR News.