When using respirators you can either get particulate filters or gas filters.
Or combo filters that do both particulate and gas.
Some of the dust that comes off what I am working with can linger in the air like a gas because of so much poweder.
Examples would be half fossilised bog oak which is hard stuff but when you do cut it becomes superfine dust that gets everywhere. Another example would be me standing out in the garden with a diamond blade angle grinder chopping paving slabs in half, the end result of that is a cloud of smoke that looks exactly like mustard gas from ww1.

So in short im pretty sure the buffer when i get it working will have much the same effect. So im pretty sure particulate filters wont be enough and I think I will need to use gas/particulate combo to avoid contamination.

Thats the respirator im using at the moment, works very well and also provides face protection.
http://www.face-fit.co.uk/images/content/f-012890.jpg