: This is NOT true in all cases. The 3M respirator that I use has organic
: chemical cartridges with dust filters over them. It DOES remove both
: chemicals and particulates.

I also have a 3M respirator and the filters on the front are not dust filters. They are pre-filters to remove the heaviest sizes of vapour, atomized paint particles in a solvent matrix, before the air passes through the canister. It simply allows the chemical cartridge to last longer.

Also, you do realize that the respirator MUST be stored in the plastic bag it comes with. If you leave it out, the charcoal will filter the air in the room which will greatly reduce it's life.

3M also makes a very good dust mask in respirator form. It has thin filters and is very light. My current one is a Gerson which is virtually identical but the filters are not interchangable.

Ian