A tip/warning for asthmatics, if you're gonna nebulize CS, go in slowly. Don't put the mouth piece of the nebulizer directly into your mouth at first. Wave the nebulized CS spray into your mouth at first at a bit of a distance. Even if your not sick, it can hit your lungs as being harsh, even at a low PPM. But, especially if you're dealing with a Upper Respiratory infection, it can be harsh at first. I found that eventually it gets easier to tolerate after a few moments and I can then put the mouthpiece into my mouth and breathe gently. Been doing it the past few nights because of a stubborn congestion and the mucous got a bit thinner and clearer using a low PPM I made with my silver Puppy Machine.