NYC 9/11 Public Portal Document
107Raddon Avenue
EMSL Analytical, Inc- Westmont, NJ. 08108
(8S6) 858-4800
Attention: Chris Gerber 9/28/01
URS
200 Orchard Ridge Drive
Suite 101
Gaithersburg, MD. 20878
Project: 89FOSPS035
Ret; Number: 360100270
Silica Analysis Performed by
X-Ray Diffraction (XRD)
Method NIOSH 7500
Nuisance Dust Airborne Silica
Sample Sample Silica Silica % Analytical
Sample ID identification Particle ID Volume Weight Conc. Weight Cone. Silica Sensitivity_
m (m m (mg) m m~ (in/m)
1 11S11 Quartz 900 0.230 0.2556 <0.004 <0.0222 N/A 0.0222
lPlIS12 Quartz 800 0.190 0.2111 <0.004 <0.0222 N/A 0.0222
1PI1S13 Quartz 900 0.080 0.0889 <0.004
lPlIS14 <0.0222 N/A 0.0222
Quartz 900 0.190 0.2111 <0.004 <0.0222 N/A 0.0222
1P11S15 Quartz 900 0.080 0.0889 <0.004 <0.0222 N/A 0.0222
Std. I3 1 0.008 mg I Quartz 0.008
Bulk Analysis! Sample ID Sample Description Silica Forms Identified
Bulk Not Submitted
M. Vargas & Jil/ernon 28 September, 2001
Analyst Date of Analysis
Disctrimcr: The laboarmry put only verify the concentration of silica on the
filter and not the liral concentration due to dam obtained by
non-laboratory pa3onneL In the absence ofa bulk dust sample, the specific
form of"tallirc silica can not be determined
Hcnec, alpba.çuar, the most prevalent form of aystallinc silica. wi11 be
assuard
NYC-WTC 000120340
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