OSHA air monitoring summary report, October 2001

NYC 9/11 Public Portal Document

OSHA SAMPLING RESULTS SUMMARY AS OF 10/24

Asbestos: A total of 587 air monitoring samples for asbestos have been taken. From 9/13 -9/22, 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 to .037 f/cc., well below OSHA’s pennissible exposure limit (PEL) of .1 f/cc.

After 9/22, sampling focused on the rubble pile and those workers working on or immediately next to it. 53 of 410 samples exceeded OSHA’s limit via PCM 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 . 1 f/cc.

Carbon Monoxide: 41 personal samples of workers on the rubble pile showed results ranging from 1 ppm to 34 ppm well below the OSHA 50 ppm permissible exposure limit

Noise: OSHA 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: As of October 22, the overwhelming majority of the 189 silica samples show no detectable levels of airborne silica. The highest sample result was approximately twice the OSHA limit, whereas the next highest level I. was less than half of this limit. Both of these levels were found on personnel working in the rubble pile; an area where OSHA continues to encourage the use of respiratory protection.

Volatile Organic Compounds: OSHA has taken 173 samples for (VOCs) such as acetaldehyde, acrylonitrile, acrolein, benzene, 2-butanone, chlorodiphenyl (PCB), ethyl benzene, formaldehyde, hexone, isocyanates e.g. (MDI)( HDI), perchloroethylene, styrene, toluene, 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 8hr OSHA Allowable Limit concentration of Ippm. This was found on a backhoe operator moving debris.

CONFIDENTIAL, CITY_2IMCl0 0_0 018 82219 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008 NYC-WTC_000178319