Safty

I'd like to just point out that there is in no way you'd pass a seal test on that mask with it positioned on your glasses as it is.
When I built barges we'd be fitted and licensed and still had issues with them not sealing. We would carbon arc gouge and have black lines of carbon from the rim of the mask to our noses when we'd remove our mask like that one. Proving a good seal is important. If you remove the filter and block the hole you should not be able to breath at all. If you can move any air you ain't sealed for sure.

Not trying to sound like a jerk randomly but want to point that out so we can be informed and stay safe as others run across this as well