NYC-WTC_000208064

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan December 19, 2001 Real-Time Air Monitoring Page 2 P.S. 89 (Manhattan) ATC Project No. 15-19125-0297

ATC measured concentrations of TVOCs using a RAE Systems, Inc. MiniRAE® photoionization detector (PID). Nitrogen oxides and SO2 were measured using a RAE Systems, Inc. VRAE® multi-gas detector. H2S was measured using a BioSystems PhD Ultra® gas detector.

The assessments were performed consistent with generally accepted indoor air quality assessment practices. As with all such assessments, there were inherent limitations created by constraints of time, operational and work practice variability, variations in indoor air quality parameters, and sampling and analytical accuracy. The results of the sampling represent conditions found on the dates of the survey and may not represent conditions found at other times. The information presented in this report should be used by the Board of Education as a guide to assess the need for further improvements in current indoor air quality control activities.

EVALUATION CRITERIA

Currently, there are no regulatory standards for indoor air quality in non-industrial buildings, such as offices and schools. For the real-time data collected, ATC uses the commonly accepted guidelines cited in the following publications:

Ventilation for Acceptable Indoor Air Quality (ASHRAE 62-1999), American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE); Thermal Environmental Conditions for Human Occupancy (ASHRAE 55-]992); Industrial Hygienists Guide to Indoor Air Quality Investigations (1993), American Industrial Hygiene Association (AIHA).

Table 1 lists target guidelines for the parameters that ATC evaluated during this investigation. Meeting one, some, or all of the listed values does not assure that acceptable indoor air quality will be achieved at all times. TABLE 1 TARGET GUIDELINES FOR INDOOR AIR QUALITY PARAMETERS EVALUATED* PARAMETER TARGET .... _______________________ Carbon Dioxide (CO,) <700 parts per million (ppm) ASHRAE 62 above background level Carbon Monoxide (CO) 9 ppm ASHRAE 62 (adopted from USEPA NPAAQS) Respirable Particulates 65 micrograms per cubic meter of USEPA NPAAQS (PM,5) air (pg/m’) 24 hour average Temperature Summer: 73-79°F at 50% RH ASHRAE 55 Winter: 68-75°F at 50% RH Relative Humidity 30 - 60 % ASHRAE 55 Total Volatile Organic 1 ppm AIHA Compounds (TVOC) Hydrogen Sulfide (H^S) 0.01 ppm (one hour) NYS DEC Sulfur Dioxide (SO,) 0.14 ppm (24-hour average) USEPA NPAAQS Nitrogen Dioxide (NO,) 0.053 ppm (aimual average) USEPA NPAAQS

USEPA = United States Environmental Protection Agency * Guidelines for NO are NPAAQS = National Primary Ambient-Air Quality Standard not available.

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NYC-WTC_000208065