ASTM D7521-13 “Standard Test Method for Determination of Asbestos in Soil” provides a new analytical option. This method covers a procedure that can:
The results produced from this method may be used for evaluation of sites contaminated with asbestos from construction, mine and manufacturing wastes, natural occurrences of asbestos (NOA) and other sources.
- Identify asbestos in soil
- Provide an estimate of the concentration in percent
- Optionally provide asbestos structures per gram
The sample is initially dried and weighed then passed through a sieve stack of 19mm, 2mm and 106 micron sieves. This divides the sample into a coarse, medium and fine fraction which are then analyzed individually by PLM procedures. Material greater than 19mm is considered to be not part of the soil sample and can be analyzed separately at client request. The method has a stated analytical sensitivity of 0.25% with optional procedures that allow for an analytical sensitivity down to 0.1% by weight. For many types of soil, especially clay soils, a wet sieving can prove superior in separating the sample into appropriate size fractions. The method has that covered with an optional wet sieving option. And for improved accuracy with highly organic soils a gravimetric reduction procedure with ashing and acid treatment is described. The fine fraction can be gravimetrically reduced and then analyzed by Transmission Electron Microscopy (TEM) via ASTM Test Method 6281.