It is possible by the categorization of the estimated levels of Individual Risk (IR) which the proposed site would impose upon them. An analysis of the consequences and likelihood of credible accident scenarios coupled with acceptable risk criteria is then undertaken. According to the results in many cases, not only required distances have not been provided but also CNG stations are commonly located in vicinity of populated areas to facilitate refuelling operations. Natural gas is in priority because of the relative abundance, ease of use, less environmental pollution, and the price is cheaper than gasoline. This study was done to identify and determine the operational deviations in one of the CNG gas compressors and proposed hazard control measures. Identification of possible causes of deviations in compressor performance and risk assessment was done in several meeting with cast HAZOP experienced experts. Seven operational deviations identified in the performance of the compressor used in CNG station includes no & less flow, more & less pressure, presence of compounds other than gas in compressor, reverse flow and more temperature. 41.34% of the risks were in acceptable range, and 58.66% was in conditionally acceptable. Prepare work instructions, worker education, fix and maintenance and regularly equipment calibration can be useful in prevention of accidents in CNG stations.