WTC emergency safety plan draft, Sept 2001

NYC 9/11 Public Portal Document

t World Trade Center Emergency Project Environmental, Safety, and Health Plan Draft - Revision A 30 September 2001

2.4.6.2 Monitoring Duration When monitoring a worker’s exposure for comparison to a published exposure limit value such as the OSHA PEL’S or ACGIH TLV’s, monitoring may need to be conducted over a full eight hour (or longer) work shift or a 10 to 15 minute period of time. F or e xtended w ork s hifts, samples should be for the shift duration and adjusted to reflect extended work duration. For asbestos, samples will be collected for maximum 8 hours during the highest expected fiber exposure, for a period of time in order to avoid overloading filters.

In some cases, monitoring may need to be continuous if there is the potential for build-up of a dangerous atmosphere. Monitoring duration can also be affected by the duration of the operation being monitored (i.e., it may only operate one hour a day) or by the length of time a worker performs an operation. Duration can also be affected by the contaminant concentration in air. Often times, higher concentrations of air contaminants will require the collection of shorter-term samples so as to avoid overloading the sample collection device being used.

2.4.6.2 Participation with DDC Sampling Program The Contractor shall participate with the DDC sampling program by allowing sampling of personnel for a variety of potential airborne contaminants. Sampling will typically occur during both shifts and require wearing sampling pumps, media and coordinate with the sampling coordinator.

2.4.6.3 Observation of Monitoring Observation of monitoring refers to two different aspects. First, all air monitoring needs to be checked throughout the day by the person performing the monitoring. When an air monitoring device, such as an air-sampling pump, is set-up and turned on, it needs to be checked for proper operation at least every 20 to 30 minutes throughout the day. All air-monitoring devices are subject to breakdown and tampering and thus they need to be periodically checked.

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