The 198.1 method is New York State Polarized Light Microscopy (PLM) method for the analysis of asbestos in buiding materials. The analysis is similar to the EPA 600 PLM method with some exceptions.
For samples containing high concentrations of asbestos, a stratified point-count technique is utilized. For samples with asbestos concentrations near the 1% level, the stratified point-count method requires a full 400-point count regiment.
Bulk materials shall be analyzed by the point counting methods in this item (198.1) or by the gravimetrically tracked matrix reduction and point-counting method for NOB materials in Item 198.6. Textiles and ceiling tiles, for example, could be prepared and analyzed through the application of 198.6. The method in this item (198.1) shall not be used for VAT, resilient floor tiles, mastic, asphalt shingles, roofing materials, paint chips, caulking, glazing and other NOB materials. Rather NOB materials must be analyzed by Item 198.4 (quantitative TEM with no disclaimers) or Item 198.6.
Sample retention time - 60 days