NYC-WTC_000232937

NYC 9/11 Public Portal Document

n Industrial Hygiene Air Sample Results Key to Air Sample Terminology

The following explanations should help in reading the data chart.

1. Sample ID - Is a unique sample identification.

2. Sample Zone - Refers to the construction sector on the site, designated by die contractor’s name.

3. Job Description - The job description of die person on whom die sample was collected.

4. Begin Date and End Date - The date(s) on which the sample was collected.

5. Begin Time and End Time - The time the sample was collected.

6. Worker - The name of the person on whom the sample was collected. If the sample was a stationary sample not worn by a worker, the word “Area” is used.

7. Analyte - This is die suspected contaminant substance that was sampled. The sampling and analysis methods are specific to this substance.

8. Results (and units) - This is the airborne concentration of the analyte found on die sample, usually as an estimated full shift time weighted average exposure. This is the number that should be compared to the occupational exposure limit (OEL). The units can be in milligrams per cubic meter (mg/cu m), parts per million (ppm), or fibers per cubic centimeter (f/cc).

9. OEL - Occupational Exposure Limit is the lower of the OSHA Permissible Exposure Limit (PEL) or ACGIH Threshold Limit Value (PEL). PELs are established by an OSHA rule-making process and are the legal occupational exposure limits. TLVs are voluntary guidelines for occupational exposure which are established by die American Conference of Governmental Industrial Hygienists (ACGIH), a private professional organi2ation.

10. Shift Adjnsted OEL - The OEL reduced to compensate for the reduced recovery time and longer exposure time posed by a 7 day per week, 12 hour shift work schedule.

11. % OEL - This is the percentage of the OET that the result represents.

12. % Shift Adjusted OEL - This is the percentage of the shift adjusted OEL that the result represents.

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NYC-WTC_000232938