D3686-20 – Standard Test Method Technical Guide

📐 Scope, Terminology, and Referenced Documents

ASTM D3686−20, officially titled “Standard Practice for Sampling Atmospheres to Collect Organic Compound Vapors (Activated Charcoal Tube Adsorption Method),” provides a standardized protocol for the collection of airborne organic vapors in workplace atmospheres. This practice, under the jurisdiction of Subcommittee D22.04 on Workplace Air Quality, specifies the use of an activated charcoal tube connected to a small, portable sampling pump worn by a worker during their shift. The values stated in SI units are the standard.

Key terminology is defined within the standard. Activated charcoal refers to charcoal, often from biological precursors like nut shells, that has undergone treatment (e.g., steam activation) to enhance its adsorptive capacity. Importantly, the scope (Section 1.2) explicitly excludes methods requiring special chemical impregnation of the charcoal media. The practice was developed in accordance with internationally recognized standardization principles (ISO/IEC 17025).

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