AS/NZS 1716-2012 Class P1 is the rating given to a respirator for filtering mechanically generated particles, e.g. from crushing, grinding, sawing and sanding.
AS/NZS 1716-2012 Class P2 is the rating given to a respirator for filtering mechanically and thermally generated particles, e.g. welding fume. These are also recommended for use in certain applications against certain infectious biological airborne particulates.
Light welding, soldering
Certain infectious aerosols
Diesel particulate material
Sanding, grinding, cutting, drilling
Plastering, rendering, excavation
With powders or dusts