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): 1920 Lab Group #: 7344 Filter Type / Filter Area: MCE 385 mm^ Lab Sample #: 1 Grid Opening Size: 0.01124 Client Sample #: 01 Area Examined: 0.04496 mm" GRID BOX: Magnification: 20,000, GRID ID: Accelerating Voltage: too KeV # Grid Openings: 4 Analysis Date: 4/6/02

Analysis Performed By: MARK PEYSAKHOV

GO. Structure Structure Type Length ID of Structure N or 7 EDS No >=05 p Amphibole (Noradb F B C M >=5p Chrys Nonasb Ambig/ND No Coord <5m Elements)

Struct = > 0.5n >5:1 Aspect Ratio Grid acceptance: '/= Positive diffraction pattern propertiesconforming to <50% undissolved filter, overlapped or folded Totals laboratory identification criteria observed <10% particulate coverage >50% coverage ate least 20 unfolded oroveriapped grid squares <5% F B C M >5p • 7= EDS spectrum conforming to laboratory holes or opaque areas identification criteria observed Chrysotile 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 NSO = No Structures Detected

CONFIDENTIAL, CITY_21MC100_003402679 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000181711