CORRESPONDENCE_2018-2023 - Laserfiche WebLink

Home Browse Search

-0- CA ELAP � Lab No. 1866 TESTING ASBESTOS TEM LABORATORIES,INC NVLAP Lab Code:10 1891-0 Oakland,CA May/06/2023 Krisneil Nair Del-Tech Geotechnical Support,Inc. 10624 Olive Avenue Oakdale,CA 95361 RE: LABORATORY JOB# 384026 Transmission electron microscopy analytical results for 5 air sample(s). Job Site: Forward Landfill Job No.: Enclosed please find results for the TEM analysis of one or more air samples.The analytical procedures were performed according to the NIOSH 7402(Revision#1) method. Prior to analysis, samples are checked for damage and disruption of the chain-of-custody seal. Samples are then logged-in,each given a unique laboratory number,and a hard copy containing all pertinent information is generated. This,and all other relevant paper work are kept with each sample throughout the analytical procedures to assure proper analysis. Preparation of air filter cassettes is performed within a HEPA filtered,Class 100 air,laminar flow clean bench environment. Cassettes are wet-wiped to remove any external contamination prior to placement into the clean bench area. Sections of the filters are removed,placed onto glass microscope slides,and collapsed in acetone vapor. The collapsed filters are plasma etched,removing the surface of the filter to a depth often percent of its original thickness,then carbon coated. The filters are further sectioned and placed carbon side up onto 200-mesh copper TEM sample grids in an acetone wick washer to remove filter material. The grids are placed into labeled containers and loaded into the microscope for analysis. TEM analysis is performed on a Philips CM-12 or EM-300 transmission electron microscope operating at 80 or 100 W, with a magnification as indicated on the analytical report. A known area of the specimen surface is scanned for particles meeting the OSHA definition of a fiber(a particle with diameter greater than 0.25 microns in width,a length greater than 5.0 microns and an aspect ratio greater than or equal to 3 to 1).Each fiber is subjected to detailed morphological and selected area diffraction(SAED)analysis. Fibers indicated as asbestos,or potentially asbestos, are further analyzed by energy dispersive X-ray(EDX)analysis as needed.Analysis continues until either completion of the grid opening containing the 50th asbestos fiber,or until 40 TEM grid openings are analyzed. Data is compiled with results reported as PCM equivalent(PCME)asbestos fibers/cc air and released to the client. Sincerely Yours, Laboratory Manager ASBESTOS TEM LABORATORIES,INC. Disclaimer- These results relate only to the samples tested as received and must not be reproduced, except in full, with the approval of the laboratory.Incorrect or illegible information supplied by the customer may adversely affect the validity of test results. This report must not be used to claim product endorsement by NVLAP or any other agency of the U.S. Government. 3431 Ettie St. • Oakland,CA 94608 • (510)704-8930 • FAX(510)704-8429 www.asbestostemlabs.com With Offices in Reno,NV(775)359-3377