NYC-WTC_000205204

NYC 9/11 Public Portal Document

OSHA SAMPLIMG RESULTS SUMMARY AS OF 11/20

Asbestos: A total of 652 air monitoring samples for asbestos have been taken. From 9/13 -9/21, 177 samples were taken in the financial district. They were taken on OSHA personnel as they walked within certain predetermined zones. Results revealed asbestos concentrations ranging from ND (none detected) to .037 fee., well below OSHA’s permissible exposure limit (PEL) of .1 fZcc.

After 9/21, sampling focused on the rubble pile and those workers working on or immediately next to it. 63 of the samples analyzed exceeded OSHA’s limit viaPCM analysis. However, upon further analysis using discriminating counting methods and/or TEM analysis, the number of asbestos fibers found dropped dramatically to below detectable levels or well below .I ftcc.

Carbon Monoxide: A total of 47 personal samples of workers on the rubble pile showed results ranging from 1 ppm to 34 ppm which are well below the OSHA 50 ppm permissible exposure limit.

Noise: 0 SHA has been conducting noise monitoring in the rubble pile. Twelve personal samples have been conducted on employees performing (or working near) various operations such as jack hammering. Employee’s exposure to the noise range from 80.6 dBA to 89 dBA. OSHA’s permissible noise exposure for construction is 90 dBA

Respirable Silica: The overwhelming majority of the 271 silica samples show no detectable levels of airborne silica. However, the highest sample result was approximately nine times the OSHA limit on pre-drillers working on the bathtub wall. The only other exposures that appear to be over die PEL level were approximately twice the OSHA limit. These two exposures occurred during; 1) rubble removal and loading operations near the Winter Garden; and 2) during the breaking up of concrete in the pit. All of the work areas where apparent overexposures to silica occurred were in the rubble pile; an area where OSHA continues to encourage the use of respiratory protection.

Volatile Organic Compounds: OSHA has taken 449 samples for (VOCs) such as acetaldehyde, acrolein, acrylonitrile, benzene, 2-butanone, carbofurans, chlorodiphenyl (PCB), ethyl benzene, formaldehyde. Freon R-22 (chlorodiflouromethane), hexone, isocyanates (e.g. MDI, TDI), perchloroethylene, phosgene, styrene, toluene, 1-3 butadiene, trichloroethylene, vinyl chloride, and xylene. Screening samples initially showed elevated levels of some organic chemicals resulting from the fires burning in the rubble pile. Subsequent personal and area samples show worker exposure levels to be below OSHA limits. However, one personal sample result for benzene was found to be at the 8-hr. OSHA Allowable Limit concentration of 1 ppm. This was found on a backhoe operator moving debris. See information below for polynuclear aromatics. Freon R-22, phosgene and dioxin.

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