OSHA sampling results summary, World Trade Center, Dec 2001

NYC 9/11 Public Portal Document

Oxides of b’iirogen/ Sulfur: Sampling on grapp: cr operators on the r bbL and Ou employees rro; mmg truck wash stations reveal ed trace ieveis of nt; oxide arid nitrocen dioxide. ..)• nersor..:: and area results wer four.c to be below OSHA limits.

.Metals; OSH.Ahas taken 653 air samples to monitor worker e.xposures to dusts, femes, oxide.-', and other compounds of .metals such as antimony, beiyllium. chromium, ctbalt. copper. iron, lead, manganese, molybdenum, nickel, vanadium, zinc, cadmium, magnesium, arsenic, and mercury. Results from these samples are generally well below the applicable OSH.A limits. However, torch cutting and burning structural steel at the rubble pile have resulted in instances of ox erexposures as follows: copper (lOitircn oxide (2 1); lead (12); and cadmium (2). Accordingly, OSH.A is recommending that workers engaged in these operations wear appropriate respiraterv protection.

lonizini; Radiation. A survey of the nibble pile was conducted on 10 22-1023 to check for latent radiation with particular attention to alpha radiation. Preliminary results show no elevated levels.

Dioxins: OSHA has taken samples for dioxin and these samples were analyzed by EPA. One initial sample, representing exposure directly on the pile, showed elevated levels of dioxins xx'hen compared to ambient background levels. This value was comparable to the levels found by EPA sampling. The dioxins at this location are being emitted from the on-going rubble fire. Additional sampling xx’as conducted around the perimeter of the pile and revealed levels that were considerably lower than those on the rubble pile. Dioxins are considered collectively as suspect human carcinogens. OSH.-k does not have a worker standard for dioxins. OSHA is coordinating with EPA, and the .Salt Lake City Analytical Laboratory' to fully assess the risk posed by the elevated levels of dioxins. Pul\nuclear .Vromatic Hydrocarbons OSHA has taken 132 samples. The majority of the samples have rot shown the presence of benzo(a)pyrene and/or one or more of five additional fused polycyclic hydrocarbons: anthracene, acridine, pyrene, chrysene and phenanthrene. Sample results to date have identified seven samples which reached or exceeded OSHA’s coal lar pitch volatile PEL ofO.Zmg.mT . These personal samples were taken on the pile on iron workers and grappler operators. OSH.A continues to strongly recommend the use of respiratory protection when working on the rubble pile. Freon R-22, Hydrogen Fluorice & Phosgene: OSH.Ahas taken 105 samples for Freon R-22 (chlorodiflouromethane). The majority of sample results received to December 17* reveal non-detectable airborne levels. Dunr.g operations invoh'ing Freon removal from the auxiliary chiller that started on 12,'5/0!, direct reading instrument revealed readings ranging from 100 ppm to one peak near a leaky valve of 500 ppm. SCBA tanks were and are being worn by workers, and masks are to be worn only when direct reading instruments reveal 850 ppm Freon and. or less than 20.4% Oxygen. OSHA does not have an exposure limit for Freon R-22. (The NIOSH REL for Freon is 1 OOOppm..) In response to information about exposure to the decomposition by-products of Freon R-22 used in the air conditioning systems of WTC towers, sampling for hydrofluoric acid (HF) had been conducted. Results for HF revealed non-detectable levels. Sample results for phosgene to date show non- detectable levels.

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