Asbestos testing correspondence, 153 Chambers Street, Apr 2002

NYC 9/11 Public Portal Document

Clean Air Testing Labs;.:Inc. 1111 Steele Btvd. Baldwin, New York 11510 Tei./Fax:(516)546-2640

Air filter samples are collected in the field and submitted to Clean Air Testing in the original cassette with appropriate descriptive paperwork, which includes the sample time, and pump •flow rate for each cassette. Clean Air Testing Labs, perform a variety of analytical tests on air samples. Listed Below is an air method regularly performed. .

and. sets 0.5 um The AHERA method uses a >5:1 fiber aspect ratio in ranges for all as the minimum fiber length. • Data is reported structures >0.5 microns in length and separately for those sample media, structures >5.0 microns in.length. Restrictions on (as.`Qbserved in the TEN) flow rate, sample loading and uniformity AHERA method are set in, order to assure reliable data. The order to provide requires that the area of analysis be variecl:in , structures/CC of air for all an analytical sensitivity of 0.005 sample. .

Settled Dust Analysis is utilized at Clean Air Testing Labs,for number of different a

for a variety applications. Analysis may involve a qualitative evaluation in' order to screen Dust Methods regularly or potential allergens or hazardous materials. Listed below is a performed by Clean Air Testing Labs, Inc. .

Method fdr..Micro-vacuum (TEN) ASTM D5755-95 Standard Test Transmission Electron Sampling and Indirect Analysis of DustbVConcentrations. Microscopy for Asbestos Structure Number to•identi-fy asbestos in dust This test method covers a procedure concentration of asbestos in the and provide an estimate of the asbestos structured per sampled dust reported as the number of test method is generally unit area of samples surface. This concentration•.of ,a•sbestos applicable for an estimate of the 1000'asbeistos structures structures starting from approximately of *.the. asbest.o's. mass is to estimate per square centimeter. If an is referred to Test. Method p5756. be determined, the user

Project #02-91 Controlled Copy on Grey Paper Page 3 of 9

NYC-WTC 000106274