Prioritization of Noise Control Solutions in an Oil Refinery Using the Noise Control Priority Index

Background: It is essential to decide on where to allocate available resources and identify priorities in noise control. Objectives: This study was performed to prioritize noise control solutions in various units of an oil refinery using the noise control priority index (NCPI). Methods: This cross-sectional study was conducted in an oil refinery in 2019. The standard of ISO 91612 was applied in the first stage to assess workplaces and determine the values of the noise pressure level (SPL). The activity of stations and the duration of workers’ presence in these stations were determined via interviews with the supervisors and senior personnel of each unit. The NCPI value in various units was determined using three variables, including the number of exposed people, exposure duration, and the weighting factor related to the sound pressure level (SPL). Finally, units were prioritized based on the final NCPI value. Results: Totally, 10 units were assessed based on the ISO9612 standard. The results revealed that 8.09% of the assessed stations were in the safe zone, 62.24% in the warning zone, and 29.66% in the hazard zone. The highest noise emission was related to the NTA unit (98 dB), and the lowest noise emission was observed in the spherical reservoir unit (84 dB). The NTA unit with 12 workers had the highest noise control priority index (1.25) among the units. Conclusions: The NCPI index makes it possible to appropriately prioritize noise control solutions in various industrial units and also implement technical and noise control plans in the oil and gas industries.