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Phenol and p-cresol were the most abundant and persistent odor-causing volatile organic compounds (VOCs) found downwind from concentrated animal feeding operations (CAFOs), while more than 200 VOCs contribute to odor. The VOC emissions from cattle and dairy production are difficult to quantify accurately because of their low concentrations, spatial variability, and the lack of appropriate instruments. To quantify two odorous VOCs, a new protocol similar to EPA method TO-14A, has been established based on the isolation flux chamber method and the use of portable gas chromatographs coupled with a purge and trap system. The objective of this research was to quantify and report phenol and p-cresol emission factors (EFs) from different ground level area sources (GLASs) in a free-stall dairy using the new protocol. Two week-long samplings were conducted in a dairy operation in Central Texas during winter and summer. Twenty nine and 37 samples were collected from six-specifically delineated GLAS (barn, loafing pen, lagoon, settling basin, silage pile, and walkway) in a free-stall dairy during the winter and summer. Thirteen VOCs were identified from a dairy operation during the sampling period, and the gas chromatograph (GC) was calibrated for phenol and p-cresol, the primary compounds found. The overall calculated EFs for phenol and p-cresol were 0.970.27 and 0.280.08 kg hd-1 yr-1, respectively, in winter. Overall calculated phenol and p-cresol EFs were 0.430.13 and 0.20.08 kg hd-1 yr-1, respectively, during summer. Overall phenol and p-cresol EFs in the winter were about 2.3 and 1.4 times, respectively, higher than those during the summer.