Background Odors in Tedlar® Bags Used for CAFO Odor Sampling

Abstract

Tedlar film is manufactured in a wet solvent process and continues to emit organiccompounds after manufacturing. Tedlar bags are used for odor sampling at concentrated animalfeeding operations (CAFOs). Odor regulations for CAFOs vary widely, but maximum detectionthresholds (DT) of 2 to 15 have been proposed downwind of feeding operations. Results at theWTAMU Olfactometry Laboratory have shown that both commercially available Tedlar bags andhomemade Tedlar bags have a detectable background odor (DTs of 20 to 60 typical) evenfollowing standard protocols for purging. Purging the bags before sampling was not effective inreducing DTs to acceptable levels, as verified with SPME analysis. Heating the Tedlar bags for 24hrs, when combined with purging immediately after heating and again prior to odor sampling,reduced background DTs to less than 12. This is an acceptable range for odor sampling at open lotbeef cattle feedyards or any other locations where DTs are expected to be greater than sixteen.