Air sampling report for silica dust, Feb 2002

NYC 9/11 Public Portal Document

104 East 25th St New York, New York 10010 www.atc-enviro.com 212.353.8280 Fax 212.353.8306 ASSOCIATES INC.

March 1, 2002

Mr. Bernard P. Orlan Director, Enx ironmental Health and Safety New York City Board of Education 28-11 Queens Plaza North Long Island City, NY 11101

Re: Air Sampling for Silica Stuyvesant High School ATC Project No. 15-19125-0246

Dear Mr. Orlan;

ATC Associates, Inc. (ATC) is pleased to provide this letter report of air sampling for silica- containing dust conducted on February 6, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling at the recommendation of H. A. Bader, a consultant to the parents’ association.

Scope of Work

ATC collected tw'clve (12) samples on February 6, 2002 for respirable dust using pre-weighed 37mm PVC filters connected to size-selective cyclones to remove the larger (non-respirable) particles prior to deposition on the filters. One (1) outdoor sample and eleven (11) indoor samples were collected per day. The samples, plus a blank, were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association accredited laboratory in Reading, PA. Analysis was performed by x-ray diffraction according to OSHA Method 142. A copy of the analytical report is attached.

Wagdi Abdelshahid and Tenzin Namgyal, Industrial Hygienists from ATC’s New York City office, conducted the sampling. The results represent conditions on the day the samples were collected.

Results

Silica was detected above the limit of detection in one of the samples. Sample ATC- 0206- STUY-S3, collected in the pool area, contained 0.0135 milligrams of silica per cubic meter of air (mg/m’). The Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) for silica-containing dust is based on the percent of quartz (SiO2) found in the dust, the higher the percentage of quartz, the lower the PEL. The formula for calculating the PEL is found in 29 CFR 1910.1000, Table Z-3. The formula is:

lOmg/m^ %SiO2 + 2

CONFIDENTIAL, CITY_21MC100_003429704 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000175070