Benzene Exposure among Employees on Norwegian Offshore Installations
Offshore workers come into contact with a variety of chemical substances during drilling, oil and gas production, and maintenance work, including benzene, which is classified as carcinogenic. In 2021, the occupational exposure limit for benzene was reduced because it was believed that illness could occur at lower levels than previously thought. This required an updated exposure assessment for offshore workers.
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The project describes measurements of benzene in the breathing zone of laboratory technicians, mechanics, process operators, and industrial cleaners on 29 offshore installations in the North Sea from 2002 to 2018. Using these exposure measurements, statistical models were created to identify factors that affected exposure and to calculate benzene exposure levels under given conditions. Such exposure models can thus provide information on how exposure levels can be reduced. Benzene measurements were then taken on offshore installations to test how well the exposure model matched measured values. The results showed a correlation between measured and calculated values, but the model somewhat overestimated the exposure level. This must be taken into account if the exposure model is to be used in risk assessments. Furthermore, the project showed that benzene exposure levels can be relatively high during specific tasks that last less than an hour. It was concluded that reducing exposure through technical measures will still be necessary since exposure to hazardous chemicals should be as low as reasonably possible.
The study was part of the Petromaks2 project and was funded by the Research Council of Norway (NFR). It was included in Hilde Ridderseth’s PhD, which was conducted under the supervision of Magne Bråtveit and co-supervisors Bjørg Eli Hollund and Jorunn Kirkeleit. Ridderseth defended her dissertation, “Benzene exposure among selected job groups on offshore petroleum installations,” on June 16, 2023.
Read the pressrelease here (text in Norwegian): Benzeneksponering i petroleumsnæringen på norsk sokkel