OSHA sampling results summary, World Trade Center, Oct 2001

NYC 9/11 Public Portal Document

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OSHA SAMPLING RESULTS SUMMARY AS OF 10/15/01 For the very latest information on OSHA sampling results please go to www.osha.gov

Asbestos: As of 10/14, a total of 452 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 fZcc., well below OSHA’s permissible exposure limit (PEL) of. 1 f/cc. After 9/22, sampling focused on the rubble pile (the keystone area of the map) where 20 of 128 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 ND or levels well below. 1 f/cc.

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

Noise: As of 10/14, OSHA has been conducting noise monitoring in the rubble pile (the keystone area of the map). Three personal samples have been conducted on employees performing and/or working near various operations such as jack hammering. Employee’s exposure to the noise range from 73.9 dose % dBA to 80.3 % dose dBA. OSHA’s permissible noise exposure for construction is 90 dBA

Silica: As of October 14“’, the overwhelming majority of the 152 silica samples show no detectable levels of airborne silica. The highest sample result was approximately twice the OSHA limit, whereas the next highest level 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; As of October 14’“, OSHA has taken 106 samples for volatile organic compounds (VOCs) such as acetaldehyde, acrylonitrile, acrolein, benzene, 2-butanone, chlorodiphenyl (PCB), dioxin, ethyl benzene, formaldehyde, hexone, isocyanates, 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.

Metals: OSHA has taken 205 air samples to monitor worker exposures to dusts, fiimes, oxides, and other compounds of metals such as antimony, beryllium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, vanadium, zinc, cadmium, arsenic, and mercury. Results from these samples are generally well below the applicable OSHA limits. However, torch cutting and burning structural steel at the pile have resulted in instances of overexposures as follows: copper (6); iron oxide (5); lead (1); and cadmium (3). Accordingly, OSHA is recommending that workers engaged'm these operations wear appropriate respiratory protection.

Other Analysis; OSHA is sampling for dioxin and isocyanates. Results are pending

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