ABOUT DECAF COFFEE
Almost all decaffeinated coffee that is found in regular grocery stores is made with the chemical method. The common solvents used on the coffee beans include methylene chloride, ethyl acetate, and highly pressurized carbon dioxide. After the green beans are moistened, they are immersed into the chosen solvent. After the solvent performs its chemical reaction, the beans are rinsed with water. The final decaffeination phase is steaming the beans. Decaffeinating coffee beans also increases their acidity. Here is a really good website with more info:
If you don't know what you're getting, you're better off drinking regular coffee as opposed to decaf! Decaf that is processed using the Swiss water method is generally ok, as far as I'm aware. You can always muscle test to see if that particular coffee is ok to drink or not - that's what I do now and haven't had a bad experience yet. (Bad decaf has made me SO SICK before, so I'm super careful now!) The best coffee to get is always going to be 100% organic coffee. It is widely available in most rural areas and tastes better too in my opinion!