Asbestos air and dust test results, BMCC, Feb 2002

NYC 9/11 Public Portal Document

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B.M.C.C. Page 4 Dust & VOC Levels November 20, 2001 TBE recommends using filters with the highest efficiency possible (per manufacturers recommendation) for the HVAC units in the portable trailers. In addition, windows and doors of the portable trailers should be kept closed as much as possible.

VOCs Air Sampling

On November 20, 2001, TBE used a direct reading, portable Photo Ionization Detector (PID) to: (1) compare levels of VOCs in various areas of the Main Building, the Portable Trailers, and outdoors, and, (2) to attempt to locate a possible point source(s) of VOCs that may be affecting the indoor air quality of the spaces.

The Mini-RAE PID is used for the measurement of most VOCs, down to a level of 0.1 ppm (part per million). The sensor consists of a sealed UV light source that emits photons which are energetic enough to ionize many trace species (particularly organics) but do not ionize the major components of air such as oxygen, nitrogen, carbon dioxide, carbon monoxide, or water. The field created on an electrode will drive any ions formed by adsorption of the UV light to the collector electrode where the current (proportional to concentration) is measured. Response time for this direct reading instrument is under 5 seconds.

TBE found that readings on November 20th were lower than the readings collected on November 13th, in both the Main Building and the portable trailers. All indoor and outdoor readings were 0.0 ppm [non-detectable] for VOCs except for one portable trailer (W-108). W-108 had a range of readings from 0.1 to 0.2 ppm.

Almost all of the indoor readings were non-detectable (0.0 ppm). TBE, in past indoor air surveys in other buildings, has detected indoor levels of VOCs using the PID in the range of 0.2-0.5 ppm, when the outdoor levels were 0.0 ppm. At B.M.C.C., there is no strong indoor point source for VOCs.

At present, no single organization develops guideline concentrations for indoor air contaminants nor are values available for all contaminants of potential concern. A number of organizations offer guideline values for selected indoor air contaminants. These values have been developed primarily for occupational settings and, in some cases, for residential settings. The values for individual VOCs are generally in the range of 5 ppm and above.

Both the fine dust particle levels and the VOC levels measured indoors and outdoors were lower on November 20th as compared to November 13th.

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