I got a P2 respirator ( I hope that's adequate enough... Is it?) after being in a cinema and making a climb through a hole in the ceiling and getting a face full of dust from my buddies foot further up the ladder. Then spotting asbestos stickers. Wonder if that was enough? How much is too much? Happened more than once too
In industry P3 is the minimum for areas which potentially contain asbestos, after all safety is paramount.
P1 Filters at least 80% of airborne particles
P2 Filters at least 94% of airborne particles
P3 Filters at least 99.95% of airborne particles
Mind you, you also have to have a face fit to check the type and size of mask provides an adequate seal otherwise it lets particles in anyway!