Air sampling letter report, NYC BOE, Nov 2001

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan November 21,2001 Air Sampling for Hydrocarbons Page 2 Stuyvesant High Schoo] ATC Project No. 15-19125-0246

TABLE 1 HC CONCENTRATION RANGES (ppm*) BY DATE

Hydrocarbon Nov. 20 Pentane <0.081-<0.082 <0.068-<0.073 <O.O71-<O.672 Acetone <0.10 <0.085-<0.091 <0.088-<0.090 Methylene chloride <0.069 <0.058-<0.062 <0.060-<0.061 Hexane <0.068-0.125 <0.061-0.184 <0.059-<0.060 Chloroform <0.049 <0.041-<0.044 <0.044 Methyl chloroform <0.044 <0.037-<0.039 <0.039 Other A Hydrocarbons <0.068 <0.057-<0.061 <0.060 Benzene <0.075 <0.063-<0.067 <0.065-<0.0’67 1,2-DichIoroethane <0.060 <0.050-<0.060 <0.051-<0.053 Trichloroethylene <0.045 <0.038-<0.040 <0.039-<0.040 Toluene <0.064 <0.054-<0.057 <0.056 Tetrachloroethylene <0.036 <0.030-<0.032 <0.031 (perchloroethylene) Chlorobenzene <0.052 <0.044-<0.047 <0.046 Ethylbenzene <0.055 <0.047-<0.050 <0.048-<0.049 Styrene <0.057 <0.047-<0.050 <0.049-<0.050 Cumene (isopropylbenzene) <0.049 <0.041-<0.044 <0.043 Xylenes (total)____________ <0.055 <0.047-<0.049 <0.048-<0.049 Other B Hydrocarbons <0.064 <0.054-<0.057 <0.056 parts per million Concentrations above the limits of detection are shown in bold face type.

The only HC present at a concentration greater than the limits of detection was hexane, which was found in samples collected on November 8 (0.125 ppm) and 14 (0.184 ppm). It was not detected in the samples collected on November 20. Hexane is an aliphatic hydrocarbon with a mild gasoline-like odor. No odor was detected by ATC during this sampling period. No indoor air quality standard exists for hexane. The Occupational Safety and health Administration (OSHA) Permissible Exposure Limit (PEL) for hexane is an eight-hour time-weighted average of 500 ppm. This is considerably above the levels that were detected or that would otherwise be expected in a school or office and it is not an applicable standard.

Airborne hydrocarbon compounds did not constitute a health concern for the occupants of the building on the days these samples were collected.

ATC appreciates the opportunity to provide this indoor air quality service to the BOE. Please call me at (212) 353-8280 extension 212 if you have any questions.

Sincerely, ATC Associate^

James R. Cohn, CIH, CSP Regional Manager, Industrial Hygiene Division

Attachment

CONFIDENTIAL, CITY_21MC100_003458684 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000179289