When you use VirtuCLEAN, your equipment is being oxidized, and that is what you smell. It is not harmful, but if it bothers you blow air through your CPAP mask for 5 minutes before putting the mask on. Don’t use any fragrance wipes or products on your CPAP equipment because it will intensify the smell. Turning your machine on and letting it run for a few minutes before wearing it will help get rid of the oxidized smell.