Optical Particle Identification incorporates physical testing with Polarized Light Microscopy (PLM) to identify particles typically large enough to be seen by the naked eye. Such particles are cellulose and synthetic fibers, asbestos, fibrous glass, dust mites and arthropod fragments, major minerals and skin fragments. This test can help isolate the source for dust buildup and is routinely utilized on job sites where indoor air quality is questioned.
Sampling of bulk materials is typically performed by the glove bag technique. Dust is commonly collected by micro-vacuuming or wipe sampling with a 4x4 inch piece of baby wipe, (no aloe or cleaners).
When "Site Standards" are taken of the various suspect materials through out the job site, the particles found in the samples can be matched to the Site Standards. This can pin point the actual source of the contamination.