NYC-WTC_000199640

NYC 9/11 Public Portal Document [Nancyjefery - Indoor Air Quality- PreiiminaQf Results Page 1 j

From'': Tholief O'Flahedy To: Kaye, Katherine Date: 10/17/01 4:00PM Subject: Indoor Air Quality- Preliminary Results

I conducted indoor air quality monitoring today on the 23rd floor at 225 B'way and so far the parameters that were monitored are o.k.

No levels of respiratory irritants including phosgene, chlorine, ammonia, ozone, sulfur dioxide, nitrous fumes, and nitrogen dioxide, were detected. No levels of chemical asphyxiants including carbon monoxide and hydrogen sulfide were detected. A trace ammount of hydrocarbons (which was negligible) was detected on the 23rd floor. No mercury vapors were detected. No natural gas was detected. No formaldehyde levels were detected. The carbon dioxide levels ranged from 300-350 ppm. The oxygen level was normal (21%). The noise levels ranged from 45.9 dBA- to 51.5 dBA. The temperature ranged from 73.5 to 75.7 degrees farenheit. The air velocity at the diffusers indicated that except for two diffusers in Classroom #1, the HVAC system was not turned on. The air velocities in most cases were less than 18 fpm. In Classroom #1, the air velocity ranged between 188 - 310 fpm. The relative humidity ranged from 30 - 31%. No characteristic odor with respect to related irritants, asphyxiants, volatile organic chemicals (VOC's), and mercaptan-like substances were noticeable despite there low odor threshold limits. Further, no levels of these contaminants were detected to support odor intensity. Additionally, there was no odor consistent in characteristic with biodecomposition.

In general, the air is acceptable. The parameters are consistent with the findings from the 22nd FL. None of the parameters approached or exceeded the permissible exposure limits. The HVAC unit needs to be turned on to further enhance ventilation. I'll prepare a detailed report and send to you shortly. Thanks.

CC: Adams, Lisa; Gonzalez, Roberta; Kambili, Chrispin; Mirsky, Stu; Porter, Valerie

CITY_21MC100_004067185

NYC-WTC_000199640