EPA Method 600/R-93/116

EPA Method 600/R-93/116 is a U.S. Environmental Protection Agency analytical procedure for identifying and quantifying asbestos in bulk building materials using polarized light microscopy (PLM). It tells the laboratory how to prepare a sample, examine fibers under polarized light, identify the asbestos mineral type, and estimate the percentage of asbestos present. It is the most commonly used method for testing suspected asbestos-containing materials like floor tiles, insulation, joint compound, and ceiling textures.

Origin

Published by the EPA in 1993 as "Method for the Determination of Asbestos in Bulk Building Materials," it updated and refined the earlier 1982 interim method (EPA 600/M4-82-020). It was developed in response to the Asbestos Hazard Emergency Response Act (AHERA) and the need for a consistent national protocol for testing building materials.

Significance in Asbestos Context

For patients trying to prove where their exposure came from, this method is often how the asbestos content of a specific product or building material gets documented. Lab reports citing EPA 600/R-93/116 may appear as evidence that the drywall, joint compound, floor tile, or insulation a person worked with actually contained asbestos, and which type (chrysotile, amosite, crocidolite, etc.). The method has known limitations: it can miss very thin fibers and may report "none detected" in materials that actually contain trace asbestos detectable only by electron microscopy, which is why a negative PLM result is not always the final word in litigation.

Example Sentence

The industrial hygienist's report identified 5% chrysotile in the joint compound samples using EPA Method 600/R-93/116, supporting the claim that the patient was exposed while remodeling homes in the 1970s.

Related Terms

Polarized Light Microscopy (PLM), Transmission Electron Microscopy (TEM), Chrysotile, AHERA, Bulk Sample Analysis, Point Counting

Notes

• If a building material relevant to your exposure history was ever tested, ask whether the lab used EPA 600/R-93/116 (PLM) or a more sensitive electron microscopy method. A PLM "non-detect" does not rule out asbestos in low-content products like joint compound or vinyl floor tile.
• Preserve any inspection reports, abatement records, or seller's disclosures from homes or worksites that may reference asbestos testing; these often cite this method by name.
• If your case involves products historically known to contain low percentages of asbestos (joint compound, gaskets, certain floor tiles), ask your legal team whether supplemental TEM testing under a method like EPA 600/R-93/116 with point counting or a TEM protocol is warranted.