Identification of volatile organic compound sources and exposure assessment of upstream oil and gas workers during well completion activities.
Snawder JE; Breitenstein MJ; Alexander-Scott M; Esswein EJ; King B; Kiefer M
Toxicologist 2014 Mar; 138(1):418
The National Institute of Occupational Safety and Health (NIOSH) is conducting research to assess chemical exposure risks to upstream oil and gas workers. Upstream oil and gas activities include site construction, drilling, well completions, extraction and well production services. Activities in each segment may present chemical hazards inherent to that activity. Well completion activities such as perforation and hydraulic fracturing, flowback, production testing and produced water management present the potential for exposures to volatile organic compounds (VOCs) including benzene, toluene, ethylbenzene, and xylenes (BTEX) and polyaromatic hydrocarbons (PAHs). Individual exposures were determined by sampling airborne VOCs in the personal breathing zone (PBZ), measurement of VOCs in exhaled breath and metabolites in urine. Identification of exposure sources and patterns of exposure were estimated through the use of photoionization detectors for VOCs, chemical specific colorimetric methods and infrared videography. VOCs including alkanes, alkenes, aromatic hydrocarbons and PAHs were detected in air samples. Real time measurement of VOCs including benzene, were highest near the headspace of tank hatches and worker exposures were reflective of time spent performing work near those sources. Mean level of benzene in PBZ samples was 0.156 ppm (0.497 mg/m3) and ranged from 0 - 0.59 ppm (0-1.88 mg/m3). Levels of BTEX in exhaled breath and urinary metabolites (BTEX and PAHs) were correlated to time spent near sources. In the case of the benzene metabolite, s-phenyl mercapturic acid the mean was 3.37 mg/g creatinine (range = 0-20 mg/g creatinine). Significant temporal variations in concentrations of VOCs (e.g., BTEX) were identified. The completions activity performed, proximity to the source, wind direction and weather conditions all effect the potential for short term and full-shift risks for exposure.
Toxicology; Exposure-levels; Oil-industry; Oils; Gas-industry; Gases; Workers; Work-environment; Hazards; Hydraulic-equipment; Volatiles; Organic-compounds; Airborne-particles; Sampling; Metabolites; Urinalysis
71-43-2; 108-88-3; 100-41-4; 1330-20-7
DART; OD; WSO
Mining: Oil and Gas Extraction
The Toxicologist. Society of Toxicology 53rd Annual Meeting and ToxExpo, March 23-27, 2014, Phonex, Arizona