If the PCM fails, which method will be utilized?

When using the Phase Contrast Microscopy (PCM) method for asbestos analysis, if this method fails to provide conclusive results, it is standard practice to utilize a different, more accurate method for analysis. The NIOSH (National Institute for Occupational Safety and Health) method 7402 is specifically designed for determining airborne asbestos fibers and serves as a confirmation technique when PCM results are deemed insufficient.

NIOSH 7402 is a transmission electron microscopy (TEM) method that can identify and quantify asbestos in air samples with a higher level of accuracy and lower detection limits compared to PCM. This capability makes it the go-to method when more detailed characterization of asbestos fibers is necessary, especially in cases where PCM may not detect all forms or types of asbestos effectively.

The other options, while relevant to asbestos testing and regulations, do not directly serve as backup methods for PCM analysis. AHERA (Asbestos Hazard Emergency Response Act) provides guidelines for asbestos management but doesn't imply a specific analytical method. PLM (Polarized Light Microscopy) is another analytical technique used for identifying asbestos in bulk materials rather than for airborne fibers, and NIOSH 6584 is another method related to asbestos but not typically utilized as a follow-up to PCM failings.

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