NYC-WTC_000220337

NYC 9/11 Public Portal Document

around the perimeter are lower than those found directly over the pile. To date, only one sample taken on the rubble pile showed dioxin levels which exceeded background levels. Ehoxins are considered collectively as suspect human carcinogens. OSHA does not have a PEL for dioxins. Polynuclear Aromatic Hydrocarbons OSHA has taken 11® samples (excluding blanks). The majority of the samples have not shown the presence of ben2o(a)pyrene and/or one or muns of five additional fused polycyclic hydroewVons: authiaccnc, acridine, pyreue, chrysene and pbencenthrene. Sample results to date have identified eight samples which reached or exceeded OSHA’s coal tar pitch volatile PEL of 0.2ing/m’. These personal samples were taken on the pile on iron workers and grapplei operators. OSHA continues to recommend the use of respiratory protection when working ia the debris field. Freon R-22, Hydrogen Fluoride & Phosgene: OSHA has taken a total of 208 samples for Freon R-22 (cblorodiflouromeihane), hydrogen fluoride, and phosgene. Only one Freon sample resulted in a detectable level of 6.4 ppm during the transfer of Freon &om the auxiliary chiller, and all other samples were none-detected. OSHA does not have an exposure limit for Freon R-22. (The NIOSH REL for Freon is 1 OOOppm..) Sampling for the decomposition products of Freon R-22, hydrofluoric acid (HF) and phosgene showed no detectable levels,

Inorganic Acids OSHA has taken approximated 151 samples for inorganic acids such as hydrochloric, phosphoric, and sulfuric acids. Throe somplea for suhurie acid HE'"-'' wcic found to exceed OSHA’s permissible exposure limit (PEL) of 1

Ik'. .Oxides of Nitrogen/ Woikere were sorting debris

Sulfur: Sampling on grappler operators on the rubble pile, and on anployees at the truck wash stations revealed trace levels of nitric oxide and nitrogen dioxide. SO2 personal and area results were found to be below OSHA limits.

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NYC-WTC_000220339