Use containers that disintegrate readily. Glass bottles don't decompose. Bottles made of polyvinyl chloride (PVC) give off lethal hydrochloric acid when incinerated. (That's the soft plastic many liquid household cleaners, shampoos, and mouthwashes come in. Don't confuse it with the stiffer polystyrene plastic, used mainly for powders.) The Food and Drug Administration has now approved PVC for food packaging, too. Don't buy it. Use decomposable or "biodegradable" pasteboard, cardboard and paper containers instead. If you can't, at least reuse non-decomposable bottles; don't junk them after one use.