4-MEI "is used commonly in soft drinks, which are something we drink a lot of, but not necessarily a dietary necessity," she told ABCNews.com. "What you know about it and what you do depends on your own level of risk tolerance. When you talk about cancer, what you change today can matter tomorrow. … Even moderating your levels of consumption, if it is big, can mitigate risks."
"It's not about all or nothing," she said. "Less is more when you are talking about exposure to 4-MEI."
PepsiCo said in a prepared statement that it "abides by the law everywhere we do business" and is now meeting California's requirements and voluntarily applying them in the rest of the country.
"We are extremely concerned about Consumer Reports' allegation that one of our products exceeds the Prop 65 standard and requires a warning label," the statement said. "We believe their conclusion is factually incorrect and reflects a serious misunderstanding of Prop 65's requirements."
"Applying the Prop 65 standard of per day exposure and based on the Consumer Report analysis, the highest amount of 4-MEI reported in Pepsi One equates to less than 14 mcg in the amount consumed per day by the average consumer. That is well below the Prop 65 labeling requirement of 29 mcg in 100 ml, and therefore does not require a warning."
Meanwhile, Consumer Reports' scientist Ranjan told ABCNews.com that its data on the concentration amounts of 4-MEI were "correct."
"They are disputing the daily consumption of soft drinks," she said of PepsiCo's position.
She said PepsiCo arrived at their conclusion by including people with low-consumption rates, such as children under the age of 2, in their averages. "We looked at the same data of regular soft drink users who can drink up to two and half servings a day," said Ranjan. "They were all over 20."
Goya Foods said in its statement it was "concerned for the health of our consumers and committed to ensuring the quality and safety of Goya products."
"We are working closely with our suppliers and continue to examine the issue. We do not directly produce Goya Malta nor its ingredients and was unaware of the level of 4-MEI found in our products and the proper labeling required in the state of California based on Prop 65. We rely on our suppliers to provide us with pertinent information and guidelines to make our products safe and of the highest quality."
Rangan said several companies, including Coca Cola, had already reduced the amounts of caramel coloring in their products. "It's an unnecessary risk we can do something about," she said.
Consumer Reports is also asking the Food and Drug Administration to make more specific labeling on products that contain 4-MEI. In Europe the specific types of coloring – 3 and 4 – are spelled out on the labels, according to Rangan.
"We also want the government to not allow a product to be called 'natural' if it contains these artificial colors," she said.
In a prepared statement for ABC News, the American Beverage Association said consumers can "rest assured that our industry's beverages are safe."
"Contrary to the conclusions of Consumer Reports, FDA has noted there is no reason at all for any health concerns, a position supported by regulatory agencies around the world. In fact, FDA has noted that a consumer 'would have to drink more than a thousand cans of soda in a day to match the doses administered in studies that showed links to cancer in rodents.' However, the companies that make caramel coloring for our members' soft drinks are now producing it to contain less 4-MEI, and nationwide use of this new caramel coloring is underway."