ENV-16-74 Sensitivity of EPA 325 to Field Handling Protocols

Description:

As refineries prepare to implement the fenceline monitoring work practice required in the updated Refinery Risk and Technology Rule1, sample handling procedures are being developed and implemented for pre-compliance monitoring trials. With the goal of generating accurate and reliable measurements, stringent protocols detailing tube deployment, retrieval, and storage requirements are advisable. Highlighting the importance of sample handling, the quality control section of EPA 325A cites accidental contamination by the field sampler as a possible reason to eliminate an outlier in the data set2. To quantify the sensitivity of EPA 325 to benzene contamination during tube handling, a series of tests was performed to quantify the impact of several likely field scenarios. The evaluated scenarios included field technicians engaging in cigarette smoking or fueling vehicle prior to sampling activities, idling work vehicle near sampling stations during tube deployment, application of insecticide to shelter prior to tube deployment, and exposure of sampled tubes to excessive temperatures during transit to the laboratory. Each experiment utilized both test samples and control samples to accurately determine the contribution of the field scenario.