I was concerned about some saying there was a strong chemical smell but when I opened up the first pack I didn't smell anything. I put it on and wore for an hour and it was doing as stated. No fogging of glasses and comfortable in breathing. I would go for these again if needed. I will donate my other ones that fogged up my glasses as will not use them again. I have to wear glasses while running my power wheelchair ........not a good idea if you can't see where you're going. Thanks for the good masks. Only issue I had is that the area where the staples are can scratch skin if not careful on putting on.