This study aims to facilitate the prioritization of hazardous air pollutants potentially emitted from petroleum refinery operations based on their carcinogenicity (C), mutagenicity (M) and reproductive toxicity (R) through hazard assessment using multi-country governmental regulatory databases. 176 hazardous air pollutants which were reported as being emitted by petroleum refineries were initially selected for hazard analysis. CMR classification for these pollutants were obtained from PETRONAS SHIELD system as well as country databases, which includes hazard classifications based on the United Nations Globally Harmonised System from Australia, China, Europe, Japan, South Korea, Malaysia, Myanmar, New Zealand, and Turkey. The most stringent classifications were assigned should there be discordance in classifications across the country databases. A scoring system that yields a maximum total score of 60 if all CMR were Category 1A and a minimum score of 0 if none of the hazards were classified was applied to quantitatively rank the pollutants. Among the countries, Japan and South Korea have the highest number of classified hazardous air pollutants across C/M/R. 121 pollutants (68.8%) have C/M/R classification or their combinations. 68 pollutants have classification for C, 40 for M and 51 for R. Vast difference in CMR classifications can be observed between the countries, with 12 pollutants’ classification ranged between 2 (suspected human C/M/R agent) to 1A (known human C/M/R agent). 18 HAP scored between 40-60, with Benzene topping the list with maximum score of 60, followed by Benzo(a)pyrene, 1,3-Butadiene, Arsenic and Cadmium.