No, it is not. Asphyxiation is very unpleasant. Hint: anything made up of matter is a chemical.

You probably also enjoy a lot of "chemicals" that are mind-altering or intoxicating without realizing it, unless you're very strict about your diet indeed. Casomorphins are delicious, you see, and can life without chocolate really be said to be enjoyable? Better skip fruit juice and bread, as well, given that they certainly include a percentage of alcohol and fermentation byproducts.