Generally, air monitoring is performed in conjunction with providing asbestos abetment oversight. Analysis of air samples, either by Phase Contrast Microscopy (PCM) or Transmission Electron Microscopy (TEM), is necessary to provide an indication of how many fibers are contained in the air prior to starting a project, during the abatement project, and upon project completion. Re-occupancy of an area should not occur until clearance air monitoring samples have been taken, analyzed, and found to be within acceptable limits.
In buildings with existing asbestos, ambient air monitoring should be performed periodically in random areas to control fiber content and to insure against potential liability. Accumulating air fiber data can be helpful in the event of a fiber release and can provide valuable baseline information during abatement projects.