Methylene chloride has a boiling point of about 40 degrees C (about 103 degrees Fahrenheit) - a drop of it on a counter would boil away on a hot day, and since it has a really high vapor pressure at any ambient temperature, it readily evaporates. That’s not to say you can be sure there’s not a single molecule of the stuff in your decaf crystals, but the chances of any substantial quantities of it present are pretty small. Even with carcinogens, the dose makes the poison; it’s not something I’d lose any sleep over.
“There’s more methylene chloride in the water that you brew your decaf with than came with the decaf roasted beans,” said James Coughlin, a food toxicology expert who consults with the coffee industry. He also called the effort to ban methylene chloride “ill-conceived.”
Coffee industry experts have also said that other decaffeination methods are less effective, more expensive, and result in lower-quality coffee.