Thai Lube Base Co Ltd, a unit of Thai Oil Plc, estimated that the fire on Sunday at its slop would cause damages of Bt5-Bt10 million.
The fire occurred at around 7pm on Sunday and were extinguished within 20 minutes with no injury.
Surong Bulakul, president of Thai Oil, said in a statement that the fire did not affect the production of the subsidiary. Its production capacity is maintained at 275,000 tonnes per year.
The company has reportedly restarted the plant today.