Which statement describes TEM usage in asbestos analysis?

• A. It is used as a backup to PLM because PLM may miss extremely narrow fibers
• B. It is never used in asbestos analysis
• C. It replaces PLM as the primary method
• D. It is used only for SEM samples

Answer: (B)

In asbestos analysis, polarized light microscopy (PLM) is the standard method for identifying asbestos fibers in bulk materials; transmission electron microscopy (TEM) is not part of routine asbestos analysis. The statement that TEM is never used reflects that, within typical inspection practice, TEM isn’t employed as a routine backup or replacement for PLM. TEM can provide high-resolution detail, but it’s expensive, time-consuming, and reserved for specialized confirmatory work in limited cases. The other options imply TEM has a routine backup role, replaces PLM, or is tied to SEM samples, which doesn’t align with standard practice in this context.