PCM Fiber Analysis Program

Method: NIOSH 7400 A Rules

  1. This method is used to estimate the airborne concentration of asbestos and other non-asbestos fibers before and after asbestos abatement.
  2.  The PCM technique has the advantage of fast turnaround time and low cost. The PCM air sampling is used for environmental monitoring, personnel monitoring, and clearance testing for minor abatement projects.
  3. The results obtained from this test demonstrate compliance with exposure limits set by NIOSH, OSHA, and other regulatory agencies for area samples as well as for personnel monitoring.
  4.  The OSHA regulations (29 CFR 1910.1001) require the analyst to only count fibers equal to or longer than 5 µm with a length-to-width ratio of 3:1 or greater.
Limitation: Fibers less than approximately 0.25 microns in diameter will not be detected with this method.

Method: NIOSH 7400 B Rules

The “B” counting rules are alternate counting rules contained in the NIOSH 7400 method. The “B” rules are slightly different from the “A” rules and are to be used for nonasbestos fiber counting such as fiberglass and man-made mineral fibers