does anyone know what is a the best face mask to use during smog inspection of a gross polluter?
A face mask that could protect the technician against, CO, HC and Nox.
I have been a smog tech since 1987 and took a break for a few years and nowI am having having a hard time breathing with a vehicles that smokes excessively.
There are no passive filters fine enough to protect you from HC, CO, or NO ... only particulates. The CO molecule is actually smaller than the O2 molecule, and has a much higher affinity for hemoglobin. You would need a sealed mask and fresh air supply to protect you from those tiny molecules, or you could tell those pukers to pound sand.
... She also wondered why we don't keep the fans on. No one noticed we don't even have the exhaust tubes that no one uses. The BAR guy noticed our building actually has exhaust chimneys for those hoses to hook up to.
You can't perform a proper visible smoke test with fans constantly running. We are required by regulation to expose ourselves repeatedly to toxins.