Inhalers are the most commonly used method of taking treatment by people with asthma.
This contains both a solution of medicine, and a propellant which is used to create the fine spray which is breathed in. These have been used effectively and safely in inhalers for decades. Whilst inhalers remain absolutely safe for the people who use them, the CFCs they contain are now known to damage the earth's ozone layer. The ozone layer protects the earth from the harmful parts of the sun's rays. If the ozone layer gets too badly damaged, it will be unable to protect the earth properly from the harmful parts of the sun's rays.