NYC 9/11 Public Portal Document
Post Cleaning Scmiples - Two air samples were collected after the first cleaning. All of
the samples were below the detection limit. Because all of the samples were below the
detection limit after the first cleaning, no additional samples were collected for analysis of
calcite.
CristobaUte
Before Cleaning Samples - Pre-cleaning air samples were not coUected.
Post P‘ Cleaning Samples - Two air samples were collected after the first cleaning. All of
the samples were below the detection limit.
Tridymite
Before Cleaning Samples - Pre-cleaning air samples were not coUected.
Post Cleaning Samples - Two air samples and four wipe samples were collected after
the first cleaning. All of the samples were below the detection limit.
MMVF
Before Cleaning Samples - Three pre-cleaning wipe samples coUected. MMVF was
detected in all three.
Post Cleaning Samples - Three air samples and five wipe samples were coUected after
the first cleaning. The results for the three air samples indicate that MMVF was present;
however, all samples were below the primary clearance criterion of 10 SZL. The results of
the five wipe samples indicate that MMVF remained present in four of the five samples
after the first cleaning, but the concentrations detected were lower than the pre-cleaning
samples. There is not a clearance criterion for MMVF in settled dust. Because the air
samples were substantially below the primary clearance criterion and the MMVF in settled
dust was reduced after the first cleaning, no additional samples were coUected for analysis
of MMVF.
PAH
Before Cleaning Samples - Three pre-cleaning wipe samples were coUected. AU three
samples were below the detection limit. The TEF for each sample was below the primary
clearance criterion.
Post P‘ Cleaning Samples - Four wipe samples were collected after the first cleaning. AU
of the samples were below the detection limit. The TEF for each sample was below the
primary clearance criterion of 300 pg/m^. Since all of the samples were below the
detection limit and the primary clearance criterion after the first cleaning, no additional
samples were collected for analysis of PAH.
Second Floor Hallway - The second floor hallway has vinyl tiles on the floor, and walls made 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
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NYC-WTC_000145741
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