3M Prefilter 5N11 x2
Here is a good safety tool when working with certain Special FX materials.
N95 Filter for use with a 501 Filter Retainer. N95 filters are for use when toxic dusts or mists, containing no oil, are a problem. Most often as a prefilter for non oil based paints or pesticides. Sold in boxes of 10. Priced and sold by the box.