Chain of Custody for Asbestos Fiber Analysis at P.S. 234M,

NYC 9/11 Public Portal Document

TEM Asbestos (air) Count Sheet Client Name: NYC BOE Volume (liters): 1928 Lab Group #: 7344 Filter Type / Filter Area: MCE 385 mm* Lab Sample #: 6 Grid Opening Size: 0.01124 Client Sample #: 06 Area Examined: 0.04496 mm^ GRID BOX: Magnification: 20,000 GRID ID: Accelerating Voltage: 100 KeV # Grid Openings: 4 Analysis Date: 4/6/02__

. Analysis Performed By: MARK PEYSAKHOV

GO. Structure Structure Type Length ID of Structure N or 'Z EDS No (Noradb F B C M >=5p Chrys Amphibole Nonasb Ambig/ND No Coord <5m Elements)

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Struct = > 0.5p > 5:1 Aspect Ratio Grid acceptance: '/= Positive diffraction pattern properties conforming to <50% undissolved filter, overlapped or folded Totals laboratory identification criteria observed <10% particulate coverage >50% coverage ate least 20 unfolded or overlapped grid squares <5% F B C M >5u 'J- EDS spectrum conforming to laboratory holes or opaque areas identification criteria observed Clirysotile AMPHIBOLES Amphibole F = Single Fiber Amosite B = Bundle (<3 fibers <1 fiber diameter apart Crocidolite Ambiguous C = Cluster (>3 Intersections) Anthophyllite Non-Asbestos Tremolite M = Matrix Non-Identified Actinolite NSD = No Structures Detected

CONFIDENTIAL, CITY_21MC100_003402684 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000181716