Chain of custody form, 125 Cedar Street, May 2002

NYC 9/11 Public Portal Document

MAY-10-2002 16.'25 P.09/13 BULK ASBESTOS AN:%LYSIS RESULTS PLM .analysis Mjjninlc g v

The samples were analyzed by industry accepted methods in accordance with EPA and ELAP methods using Polarized Light Microscopy (PLM) with dispersion staining in conjunction with stereoscopical analysis. Point counts are pe Formed on sampIcs regulate:l by these agencies. .be Environmental Laboratory Approval Program (I LAP) has detertnined that analysis of non-triable organically bound mate;i lls (i..s. floor tile; roofing, etc.) is not reliable when performed by Polarized Light Microscopy (PLM) method. Therefore, if this analysis included that of non-friable materials under PLM and the results were negative. ATC must add this disclaimer to maintain our ELAP accreditation: "Polarized light microscopy is not consistently reliable in detecting asbestos in pool coverings and similar non- friable organically bound materials. Quantitative 'rr;rnsmission Electron Microscopy is ciirreatly the only method that can be used to determine if this material can be cor,,,dared or treated as non-asbestos containing". Samples that are layered and analyzed by the gravimetric method as cotnposites (NESI-IAp, AHERA) should be considered positive if results are between trace and 1°'.. unless every layer is analyzed separately.

EPA does not regulate mixed mineral assemblage like the anthophyllite-tale intergrowth that is found in paint and caulking unless these materials contain asbestos in an amount greater titan 1%. Anthophyllite detected in paint and caulking samples might be a talc intergrowth.

ATC has the capabilit;, of performing TEM confirmation if so desired.

All bulk sunpte reports are checked and reviewed two times. Unused portions of samples V °e archived for three months unless client requests special handling. This rcp-rt must not be used by the client to claim product endorsement by NIST or any agency of the U.S. government.

ATC Associates live, is not responsible for sample collection and analytical procedures not performed by our laboratory. This report may not be reproduced in part without the laboratory permission.

ATC Associates will nut be liable for analytical results from samples that are not prepared according to the standard methods (EPA, ELAP. etc.) used by the laboratory (e.g. composite samples from different locations, samples with instifficient volumes, straight TEM samples without gravimetric procedures. add duat samples).

Lahernto Ecuinment

Laboratory analysis was accomplished utilizing Olympus B}-I-2 Microscopes,

Quality Control

ATC Associates Inc. is accredited by NVLAP (Lab Code 1137-00) and NY State DOH ELAP (Lab ID 10879) for bulk and air fiber analyses. ATC participates in the Bulk Asbestos Sample Quality Assurance Programs for NVLAP and ELAP and maintains an in-house QC/QA program for bulk samples whereby 10% of all submitted samples are reanalyzed and documented in a Quality Control Manual. ATC also participates in a quarterly round robin QC/QA program for bulk samples with several accredited laborawries throughout the United States. Current and past QC/QA program results are a 'ailable in the laboratory for inspection.

The phase abundances provided by point count may be considered within the limits of variability inherent in the method employed. The sample results are accurate to within +!•5- 10 percent measured by the calibrated visual estimate method. For point counts the detection limit of 0.25% is based on one asbestos point counted over 400 non-empty points. if c1 point counted and asbestos is detected, a trace result will he reported. Trace is < 1% ACivl.

The analyses were supervised by Milt: is Lowd, Director of Laboratory Services, who has extensive experience in asbestos analysis by PLM and other methods. Please contact me regarding any questions relating to these materials at 212-353.8280 Ext. 247.

Sincerely,

Milena B. Loved

Diree:or of Laboratory Services

NYC-WTC 000108092