NYC-WTC_000195194

NYC 9/11 Public Portal Document

MMVF Before Cleaning Samples - Four wipe samples were collected. MMVF was detected in the wipe samples in concentrations from 286.16 S/cm^ to 2174.79 S/cm .

Post Cleaning Samples - Three air samples and five wipe samples were collected after the first cleaning. All of the air sample results indicate that MMVF was present, but at levels below the primary clearance criterion of 10 S/L. All of the wipe sample results were in the range of 57.23 S/cm^ to 572.31 S/cm^, which is lower than the pre-cleaning range. This indicates that the cleaning techniques were effective at reducing MMVF concentrations. «r PAH Before Cleaning Samples - Four wipe samples were collected. Three of the four samples «r were below the detection limit with TEF values below the primary clearance criterion. The fourth sample had six PAH compounds detected; the calculated TEF slightly exceeded the primary clearance criterion of 300 pg/m^ with a value of 325.8 pg/m^.

w Post P‘ Cleaning Samples - Four wipe samples were collected. All four samples were below the detection limit, and the TEF for each sample was below the primary clearance criterion of300 pg/m\

Fourth Floor Hallway - The fourth floor hallway is an area with plywood floors and walls made w of sheet rock covered with wallpaper glue. The ceiling is also made of sheet rock, and is painted.

Cleaning Method - This area was cleaned using Test 4A and Test 4B. Test 4A used an industrial HEPA-filtered vacuum and an AFD, while Test 4B consisted of a soap and water wet wipe of only the ceiling.

Cleaning Results - This unit met the clearance criteria listed in Table 1.0 for each compound after being cleaned once.

Asbestos 4) Before Cleaning Samples - There were no samples collected before cleaning.

Post P‘ Cleaning Samples - One sample was collected after cleaning. The air sample was analyzed using PCM, TEM AHERA, and PCMe The PCM result was below the I* secondary numeric criterion of 0.01 ffcc. Similarly, the TEM AHERA result was below the secondary numeric criterion of 0.022 S/cc. The PCMe result was below the primary clearance criterion of 0.0009 S/cc with the sample being below the detection limit. w w Diojdn Before Cleaning Samples - There were no samples collected before cleaning.

Post P‘ Cleaning Samples - There were no post- cleaning samples collected.

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NYC-WTC_000195265