Volatile Hydrocarbon Exposure During In Situ Burning of Crude Oil at Sea

Abstract

Personal exposure of response workers (and other personnel) to volatile hydrocarbons and benzene was monitored as part of the Newfoundland Offshore Burn Experiment (NOBE), a major oil spill combustion trial organized by Environment Canada and sponsored by over 25 governmental and private organizations from Canada and the United States. Benzene and total petroleum hydrocarbons were monitored using organic vapor monitors and charcoal tubes and analyzed by gas chromatography. Benzene and total petroleum hydrocarbon exposures were generally very low during experiments involving in situ burning (the controlled combustion of oil on water); over 95% of the determinations were below the analytical limit of detection, which was usually less than 0.1 ppm. In situ burning of unweathered crude oil at an accidental oil spill would probably be associated with higher exposure to benzene and other volatile hydrocarbons than at NOBE if the crude (1) had a higher natural benzene content than the Alberta Sweet Mixed Blend used at NOBE, (2) was less weathered than the oil in this study, or (3) had a larger evaporating crude surface area. Under the conditions of this experiment, the in situ burning process itself did not appear to present a significant benzene exposure risk to spill response personnel. Although these results suggest that the in situ burning process itself does not appear to present a significant benzene exposure risk to spill response personnel, the hazards of each accidental spill scene (regardless of spill countermeasures employed) must be evaluated and understood to assure worker safety.