New Delhi, July 16 -- Three petrol pump owners flagged a fresh challenge with E20 fuel - which contains 20 per cent ethanol and 80 per cent petrol. The fault relates to ethanol's moisture-absorbing nature.

Petrol pump owners told The Hindu that ethanol's hygroscopic nature (ability to attract and hold water molecules from its surrounding environment) is leading to contamination of their E20 stock during monsoons, and in coastal areas, because the existing underground storage tanks were designed for conventional petrol, not higher ethanol blends.

"The underground tanks that store fuel often have some amount of water due to ingress during rains or moisture or condensation or from the fuel tanker that brings petrol to the petrol pump," an ...