I purchased this for farm and shop use. I had been coughing for a day or so every time I used the tractor discing, mowing or spraying despite using a 3M paper disposable mask. My wife persuaded me to get a respirator - instead of the paper masks - when doing tractor chores. I went on Amazon and based on the reviews as well as my dual need for chemical and dust filtration selected the 3M Half Facepiece Disposable Respirator Assembly 5301/21577.
Last week I sprayed pre-emergent and herbicides in the vineyard and orchard for 6 hours each for two days. No coughing or difficulty breathing afterwards. This 3M unit worked for chemical filtering great. Later that same week, I refinished two doors inside the shop, using paint remover, naphtha, mineral spirits and making lots of sawdust with the power sander. Again, no coughing later or difficulty breathing. It works.
Fours stars because after 6 hours on the tractor you sweat under the mask and the back neck strap attachment/coupler can scratch/irritate the back of your neck with longer work times - especially when swiveling your head all the time on a tractor. A small price to pay for no coughing, however an easy to fix design flaw for the engineers at 3M to fix. Otherwise 5 stars.
Highly recommend for dusty/particle and chemical use versus the paper mask for protection.