Feeling virtuous because you've switched to decaf for your morning brew? Then you might be dismayed to learn that a common process used to strip caffeine from coffee beans involves a chemical that has been linked to detrimental health effects.
Approximately 10% of Americans – 26 million people – drink decaf coffee, which is most frequently made using the so-called "European method." This process involves steaming raw, green coffee beans until the pores open and then soaking them in chemicals, including methylene chloride, which bonds to caffeine and removes it.
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The level of the compound left after the process is "well below" the concentration allowed by the U.S. Food and Drug Administration, according to the American Chemical Society. Methylene chloride, however, may be a carcinogen, although not enough research has been done to determine at what level of exposure. The compound can harm the eyes, skin, liver and heart, according to the Centers for Disease Control and Prevention.
The FDA filed a petition in January advocating for the ban or restriction of several solvents, including methylene chloride, in American food and drugs, because they have been linked to cancer in humans and animals. The Environmental Defense Fund, Breast Cancer Prevention Partners, Center for Environmental Health and Environmental Working Group are backing the push. In late April, the Environmental Protection Agency finalized a ban on its use in paint strippers.
Companies do not have to disclose whether they use chemicals during decaffeination, but the Clean Label Project, a nonprofit with the mission of bringing truth and transparency to food and product labeling, lists on its website brands they have tested for the presence of methylene chloride.
At least two other, chemical-free ways to make decaf coffee exist. The Swiss Water method soaks green coffee beans in water for a long period, slowly draining the caffeine from them. The CO2 method uses carbon dioxide to extract caffeine from coffee beans.
But decaf coffee does not mean it is entirely caffeine free. Decaffeination removes 97% or more, but not all, of the caffeine.