Simply Spray is non-toxic, non-flammable and has no fume odours. The propellant in the can is very safe and is the same propellant used with food, such as whip cream. The propellant is odourless. Occasionally, you may smell a faint paint odour if you are using a large number of cans indoors. If you have sensitivities, you should use the product in a ventilated area to be on the safe side.