HAZARD AND OPERABILITY (HAZOP) STUDY IS THE MOST WIDELY USED METHODOLOGY IN THE WORLD AS A TOOL FOR HAZARDS IDENTIFICATION. SULFUR RECOVERY UNIT (SRU) IS ONE OF THE MOST IMPORTANT PARTS OF GAS PURIFICATION PROCESS WHERE THE ACID GAS IN THE FORM OF H2S IS CONVERTED TO LIQUID ELEMENTAL SULFUR. THIS PAPER PRESENTS A HAZARD EVALUATION FOR THE CONVERTER SECTIONS USING HAZOP PROCEDURE. ALL OF THE DEVIATIONS WERE CONSIDERED BY HAZOP TEAM AND THE RECOMMENDATIONS WERE SUGGESTED TO REDUCE THE LIKELIHOOD OF CONSEQUENCES THAT MOSTLY WERE RELATED TO THE ENVIRONMENTAL RISK. THE EFFICIENCY OF SRU IS STRONGLY ASSOCIATED WITH THE PERFORMANCE OF CONVERTERS. DECREASE IN EFFICIENCY OF SRU CAN LEAD TO MORE SO2 EMISSION AND ENVIRONMENTAL POLLUTION. EFFICIENCY DROP IS THE MOST IMPORTANT CONSEQUENCE OF ENTRANCE OF EXCESS AIR INTO CATALYTIC CONVERTERS. PURGING, DOUBLE BLOCK AND BLEED SYSTEMS SHOULD BE INSTALLED AND COMMISSIONING PROCEDURE SHOULD BE PERFORMED COMPLETELY.