Asbestos removal evaluation lab report, schools

NYC 9/11 Public Portal Document | | | { ’ + iis pity <i, , t Rete res se Saree ety nn Ss > “$46 SETTLED ASBESTOS GUST SAMPLING AND ANALYSIS seconds, The entire cap of the cassctte is removed and the suspension poured into a pre-cleaned 200 ml glass medical specimen bottle. All visible traces of the sample are rinsed into the specimen bottle with a plastic squirt bottle of filtered water. This procedure is repeated two additlonal times for a total of three washings. Next, the nozzle is rinsed (wo or three times into the specimen bottle. Typically, the total amount of water used in the rinse is approximately 70 to 75 mi. The water level in the specimen bottle is then carefully adjusted to 100 mi with prefiltered water. The pH of the water is adjusted to 3-4 using a 1.0% HCi solution, aoe nes enuresis capped and ultrasonicated for three minutes to make a uniform Two minutes of setilng, & measured volume of suspension ie extracted with a graduated pipette inserted halfway into the sample solution. The aliquot is mixed with particle-free water in the filter funne! and filtered through a 0.22 ym pore size mixed cellulose ester filter backed by an 3.0 pm pore size cellulose ester Alter. The filter is dried and prepared according to the AHERA air samptc preparation procedure. A sample blank is prepared in an identical way as the samplc. although no carpet segment is actually vacuumed. ASBESTOS COUNTING tm the transmission electron microscope, the number of each type of asbestos Structures, chrysolile or amphibole, is determined by examining a known area on the grid in terms of a number of grid openings. The asbestos fibers are identified on the basis of morphology, selected arca electron diffraction (SAED) and/or energy dispersive X-ray spectrometry (EDS). The samples are counted following the EPA (Yamate) Provisional Method or the AHERA counting rules. The choice of counting methods écpends on the particutar interest of the analyst. The Yamate counting rules provide more information about the sizes of structures found by the analyst than do the AHERA counting rules. The amount of asbestos in a given sample is expressed as structures per square foot, structures per square centimeter or structures per square meter, The value is calculated using the following equation: EFA =x 100 x NOSTR = Structures/area of carpet GO x GOA x SPL x V of the dante nh imranenateneniet cept ns ce ethane ert sant inc A namanaetattitinmemnnme a 9 4 NYC-WTC_000144621