NYC-WTC_000215187

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan March 1,2002 Indoor Air Quality Assessment Page 2 H.S. for Leadership & Public Service fM894') ATC Project No. 15-19125-0290 , The assessment was 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 BOE as a guide to assess the need for furtlier 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:

yenlilaiion for Acceptable Indoor Air Quality (ASHHAE 62-1999), American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE); Thermal Environmental Conditions for Human Occupancy (ASHEAE 55-1992); 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

PARAMETE-R s ■TARGET^LEVEL, T A^EN'C^...QR<':::.>B OI^^jZATIofet? Carbon Dioxide <IQ0 parts per million (ppm) ASHRAE 62 (CO2) above background level Carbon Monoxide 9 ppip ASHRAE 62 (adopted from (CO) USEPA NPAAQS) Respirable 65 micrograms per cubic meter USEPA NPAAQS Particulates (PM2.5) of air (pg/m^) 24-hour average 40 pg/nU 24-hour average USEPA - Recommendation for children / sensitive individuals 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 Compounds 1 ppm AIHA (TVOC) USEPA = United States Environmental Protection Agency NPAAQS = National Primary Ambient-Air Quality Standard AIHA = American Industrial Hygiene Association

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NYC-WTC_000215188