Q.  In your article on decaffeinated coffee, you say that "Almost all decaffeinated coffee is produced using a Swiss water process or carbon dioxide extraction, both of which are quite harmless.” I have heard that Starbucks uses a chemical process to decaffeinate their coffee and I understand this is harmful for us and the environment.  What are your thoughts on this?

A.  After receiving your email, I got in touch with Starbucks and was surprised – and disappointed – to learn that they do, in fact, use a solvent called methylene chloride to produce all but two of their decaffeinated coffees. The decaf Komodo Dragon Blend and the VIA Instant Decaf Italian Roast are the only two made without chemical solvents. 

The decaf Komodo Dragon Blend and the VIA Instant Decaf Italian Roast are the only two made with a non-toxic Swiss water process.

Methylene chloride is a toxic compound and suspected carcinogen. As with most solvents, you don't want to breath the fumes or let it touch your skin. Let me reassure you, however, that the coffee itself is not the concern here. Decaffeinated coffee contains no detectable traces of the chemical because it is burned off by the high roasting temperatures.  You'd be much more likely to come in contact with this chemical in paint thinners or adhesives. 

In order to protect workers from occupational exposure, opens in a new windowOSHA regulates the use of methylene chloride in the workplace. The EPA, meanwhile, watches out for opens in a new windowcontamination of soil and ground water.

While industrial use is a potential source of contamination, a much larger threat may be consumers who put paint thinners and other solvents into the general trash instead of dropping the stuff off at hazardous waste facilities, where they belong. Although we're often quick to jump on industry for polluting the environment, the truth is that uninformed (or indifferent) consumers are sometimes the biggest problem.

But back to coffee: To tell you the truth, when I stop at Starbucks, I'm usually not interested in decaf! (See: Benefits of Caffeine) But I'm so glad you brought this to our attention so that we can all make more informed choices.