Mobile laboratory data

Mobile Lab results:

By definition, the OEL is an 8-hour time weighted average that establishes a limit for personnel exposures to hazardous chemicals. It is the exposure level to which a person may be exposed for 8 hours/day, 40 hours/week for 40 years and have no expectation of adverse health effects. In this study, area vapor concentration measurements were made to better understand the hazardous vapor exposures that workers may receive. These measurements are only compared to OEL concentrations to give them context. It is not accurate nor appropriate to interpret these short duration measurements (2-seconds) as worker exposures levels. Since the OEL is defined as a time weighted average, it is more appropriate to compare it to daily average vapor concentrations. Short duration excursions above the OEL concentration are not significant.

The PTR-MS results for but-3-en-2-one + 2,3 dihydrofuran + 2,5 dihydrofuran should not be reported without appropriate caveat because

1) the results are suspect due to a known biogenic interferant (methacrolein) that is expected to be in concentrations that occasionally exceed the dihydrofuran OEL and

2) this combination of COPCs have OEL concentrations that differ by a factor of 200, which provide widely variant bases for such results as ‘no. measurement between AL and OEL’ and ‘maximum continuous time above OEL.’ Nitrosamine results are also suspect due to interferants identified during the background study.