NYC-WTC_000227030

NYC 9/11 Public Portal Document

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 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 55-1992); 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.

TABLEI TARGET GUIDELINES FOR INDOOR AIR QUALITY PARAMETERS EVALUATED

PARAMETER “ ofcXNizkT^# I' V Carbon Dioxide <700 parts per million (ppm) ASHRAE 62 (CO2)_____________ above background level Carbon Monoxide 9 ppm ASHRAE 62 (adopted from (CO)______________ USEPA NPAAQS) Respirable 65 micrograms per cubic meter USEPA NPAAQS Particulates (PM2.5) of air (pg/m3) 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 1 ppm Organic Compounds AIHA (TVOC) USEPA = United States Environmental Protection Agency NPAAQS = National Primary Ambient-Air Quality Standard AIHA = American Industrial Hygiene Association

Real-Time Environmental Measurements

ATC collected one hundred and twenty-seven (127) sets of real-time environmental measurements consisting of one hundred and twenty-five (125) in the school building and two (2) outdoors. All ten floors of the school were surveyed. These results are described below. Field data sheets are found in Attachment 1. Readings began at 8:45 A.M. and concluded after 3:15 P.M.

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NYC-WTC_000227031