Effect of Sample Preparation on Observed Airborne Fiber Characteristics

Natural occurrences of asbestos and potential exposures to such materials have drawn significant public and regulatory interest in recent years. Proposed revisions to a published analytical method (ASTM D7200) that is designed to monitor airborne fiber concentrations are based on data developed using inappropriate sample preparation strategies, including over-grinding the samples and the use of ultrasonication. Tests demonstrating the effects of grinding and preparation of asbestos minerals have been conducted. Sample preparation procedures used by some laboratories destroy the characteristics of asbestos, thereby limiting the usefulness of ASTM D7200 and similar analytical methods. The effects of sample preparation on the morphology of particles must be considered when creating or revising asbestos analytical procedures.