NYC-WTC_000229622

NYC 9/11 Public Portal Document

liberty Mutual.

Industrial Hygiene Air Sample Results Summary for Weeks of 11/25 and 12/2

Highest Analyte - The analyte found in the highest concentration with respect to its occupational exposure limit.

Highest Result - The concentration ofthe highest analyte.

OSHA PEL - This is the Permissible Exposure Limit (PEL) for the highest analyte. PELs are established by an OSHA rule-making process and are the legal occupational exposure standards.

ACGHITLV - Ulis is the Threshold Limit Value (TLV) for the highest analyte. TLVs are voluntary guidelines for occupational exposure which are established by the American Conference of Governmental Industrial Hygienists, a private professional organization.

Highest Result / % of OEL - This is the percentage of the occupational exposure limit (OEL) that the highest result represents. This is the value in the “Highest Result” column divided by the lower of either the PEL or TLV and converted to a percentage.

#of NQs - This is the number ofanalyses that repOTted that concentration as “not quantifiable” (NQ).

% of NQ - This is the percent of the total analyses which were reported as “not quantifiable”.

If you have any questions concerning this information or would like further details about these results, feel fi-ee to contact the Liberty Mutual Industrial Hygienist on duty @ 917-566-2576.

Mike Ramsey, CSP,CIH Senior Industrial Hygienist Liberty Mutual Insurance Group

12/20/01

CONFIDENTIAL INSURANCE INFORMATION, CITY_21MC100_007971939 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

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