Of course, I cannot know if the filtration is as advertised as I cannot test them in a lab. But after a day of spraying, I never smelled any of the chemical come through into the mask. I was surprised as to the fit of the mask. I have a difficult to fit face and facial hair so I did not expect any mask to be a one-size fit's all.  For me, anyway I just had to trim a bit of m hair and snug up the straps to get a good seal. Every respirator has limited air flow making real labor a test of the flow. I was mucking around in 10 foot high cattails and mud, carrying 40 lbs of chemical on my back on a hot day, with protective clothing. It was able to keep up with my heavy breathing better than I thought it would. It is not any more uncomfortable than most respirators, light, and the strapping system is easy and not annoying. For the price, I'm delighted.