Healthy Indoors Magazine
Issue link: https://hi.healthyindoors.com/i/1489776
34 | December 2022 T he Environmental Information Association (EIA) held its annual conference last March in Phoenix, Arizona. There were several sessions regarding as- bestos where attendees discussed the federal re- quirements regarding asbestos clearance air sam- pling. Based on those discussions the authors thought it was time to write an article on this topic to clarify many issues. This article is based on federal requirements. There are state/local programs that can have varying requirements in locations such as New York State and New York City (NYC) and others. We will look at the NYC issues later in this document. For asbestos abatement (most often removal) the final clear- ance air sampling requirements for schools (K-12, public and pri- vate) are defined by the Environmental Protection Agency's (EPA) rules, Asbestos-Containing Materials in Schools (40 CFR Part 763, Subpart E, known in industry by the statute acronym as AHERA) 1 . The requirements are found in two sections of the rule • Response Actions; §763.90 (i) • Appendix A (to Subpart E) "Interim TEM Analytical Meth- ods…to Determine Completion of Response Actions", II. Mandatory Transmission Electron Microscopy Method For all intents and purposes, these methods serve as the indus- try standard when final clearance is performed for most asbestos abatement projects, especially when areas are to be re-occupied. We'll discuss applicability issues as we go. The AHERA regulation discusses the requirement for aggres- sive clearance sampling. Aggressive sampling means floors, ceilings, and walls shall be swept with the exhaust of a minimum one (1) horsepower leaf blower. Some states and specifications may also require the use of fans as described in the non-mandatory section of Appendix A. As defined by AHERA rules, final clearance air sampling can be performed by phase contrast microscopy (PCM) methodology for projects less than or equal to 160 square feet (ft 2 ) or 260 linear feet (LF) by the National Institute for Occupational Safety and Health (NIOSH) method 7400, Asbestos and Other Fibers by PCM (Issue 3: 14 June 2019) 2 . For projects greater than 160 ft 2 or 260 LF clearance shall be done by the AHERA transmission elec- tron microscopy (TEM) methods. There are some similarities between the AHERA TEM and NIOSH 7400 methods. For example, the AHERA TEM method allows the use of either a 25-millimeter (mm) filter cassette or a 37mm filter cassette. The last time 37-mm cassettes were used was the old asbestos sampling method P&CAM 239. 37-mm cassettes INdustry INdustry You Can't Handle the Truth... About Final Clearance Air Sampling By Angelo Garcia III and Thomas Laubenthal TEM Analysis (MVA Analytical)