In a lube oil plant of a petroleum refinery, during the isomerization of wax, the high pressure reactor (23 meters high, 1m diameter, 64 bar, 430-480 °C) ruptured, releasing gas composed by 70 % of hydrogen and 30 % of gaseous hydrocarbons (that is methane, ethane and others). The release gas was ignited and a fire developed in the plant area where operators and engineers were working. After the shut-down of the plant, 4 on-site firemen brigade provided to extinguish the fire. No people were injured. The fire damaged the unit and adjacent structures.

The initial investigations revealed anomalies inside the temperature control system with the absence of a high temperature trip device, an inadequate cooling facilities and an inadequate operational procedures and training of the employees.