NYC-WTC_000205245

NYC 9/11 Public Portal Document

Liberty Mutual / ATC Measurement Data

Weekly Summary

#of #of Highest Highest OSHA ACGIH Highest Result Job With Highest #OfNQs %NQ Comments Week of: Agent Class Samples Analyses Analyte Result PEL TLV % of OEL Exposure

12/1W1 Total Dust/Metals 4 80 calcium 0.054 mg/m3 10 mg/mS lOugffnS 0.064% of PEL Torch Cutter 47 59% 12/11/01 Resp. Dust/Silica 2 6 Quartz NQ 0.1 mg/mS* 0.05 mg/m3 0% of TLV Grappter Operator 5 83% 12/11/01 Aromatics 12 48 Toluene 0.075 ppm 200 ppm 50 ppm <0.01 %of%ofTLV Torch Cutter 42 88% 12/11/01 Aldehydes 6 48 Formaldehyde 0.017 ppm 0.76 ppm 0 3 ppm (Ceiling) 2.3% of PEL Flagger 42 88% 12/1W1 PAHs 84 Total PAHs 1.35 200 ug/ni3 200ugAtT3 0.88% of PEL Crane operator 68 01% 12/1W1 Asbestos 7 Fibers 0.038 0.1 f/cc 0.1 f/cc 38% of PEL Spotter 0 0% 12/11/01 Acids 2 12 N/A AH'Too Low to Quantify" 12 100% 12/11A31 Ozone 5 5 N/A All 'Too Low to Quantify" 5 100% 12/11/01 Diesel Fune 11 Inorgarsc Carbon 0.075 n>g/m3 O.Smg/mS a.Smg/mO 2.2 % of PEL Torch Cutter 1 9%

Totals: 53 301

12/17/01 Total Dust/Metals 2 40 calctum mg/m3 10mgzm3 l0mg/m3 10% Of PEL Torch Cutter 122 305% 12/17/01 Rasp. Dust/SiHca 3 Quartz 0.41 mg/m3 0.1mg/m3 • 0.05 mg/m3 82Q % Of the PEL Grappler WTC#4 1 33% 12/17/01 PAHs 3 48 Total PAHs VOID 12/17/01 Asbestos 6 6 Fibers 0.064 0,1 f/cc 0.1 f/cc 64% of PEL Spotter 0 0% 12^17/01 Acids 8 48 suihric 1.2 mg/m3 1 mg/mS 1mg/m3 120% of TLV Torch Cutter WTC 1 Depr. 12 25% 12/17/01 Ozone 2 2 ozone NQ All 'Too Low to Quantify" 2 100% 12/17/01 hydrogen sufiide 1 1 hyrogen sulfide NQ All'T00 Low to Quantify" 1 100% Totals: 22 147

Notes:

The PEL for quartz is deterrrtned by the formula PEL = 10 mgZm3 / (% quartz +2). For dusts iMth high quartz content this AorKs out to De a quartz concentration of approximately 0.1 mg/m3.

"OEL" = ‘occupational exposure ImH". A generic term encompassing PELS, TLVs and other workplace exposure limits.

"NQ" = ‘not quantifiabie". Substance was was not present in sufficient quantity in the sample to report a firm value for the concentration All quantification levels for the sampling methods used are well below occupational exposure limits.

The area samples for hydrogen sulfide were taken near suspected sources and were not representative of worker exposure.

NYC-WTC_000205245