Blend effect, contamination, and adulteration are three different problems

Ethanol is hygroscopic — it actively absorbs moisture from its surroundings — and is a stronger solvent than pure petrol. Past a saturation point (commonly cited around 0.5% water by volume), the ethanol-water mixture separates from the petrol and settles at the bottom of a tank — exactly where dispensing pumps draw fuel from. This is “phase separation.”

Ethanol moves mostly by rail and road tanker to OMC depots for blending — independent industry analysis of this value chain describes it bluntly as “largely unorganized”, with dedicated “Ethanol Blending Corridors” still only planned under the 2022 National Logistics Policy, not built industry value-chain analysis. Decades of international materials science explain why ethanol generally isn’t piped through ordinary petroleum infrastructure in the first place: chloride, water, and pH together drive stress corrosion cracking in carbon steel peer-reviewed materials research.

What has been done: OMCs replaced dispenser seals and washers with neoprene rubber; testing frequency has increased (water-ingress checks 8–12 times a day at 87,000+ outlets, per the Ministry). What hasn’t: no confirmed nationwide audit or certification programme for underground storage tanks built for straight petrol; no region-specific response despite documented higher risk in coastal and high-rainfall areas; and no published framework for who compensates a motorist when contaminated fuel — not the blend itself — causes damage.