Fuel Ethers and Groundwater

EFOA is committed to continuous promote best practices for fuel ethers’ handling as part of its goal to reduce and prevent contamination in surface and groundwater.

The use of fuel ethers and other components in petrol has led to detectable small concentrations in the environment. The source of these background levels was the partially burned petrol (white smoke) that occurs when a car is first started and before the catalytic converter is warm enough to work.

The impact of the background concentrations has been analysed intensively in the science based EU-Risk Assessment on MTBE. The Risk Assessment concluded that the measured concentrations of MTBE are far below any threshold where they could pose a possible concern to people’s health. This assessment for MTBE is valid for ETBE and TAME as well.

With the increase in use of fuel ethers in recent years, the average background concentration has not increased. This results from the steady improvement in car technology (faster warming catalysts) and the introduction of vapour recovery equipment at petrol stations, which leafs to lower emissions, and affects the concentration level. As such, the background concentration levels are far below any critical limit.

The EU-Risk Assessment for MTBE concluded that, although concerns do exist regarding water contamination, the measured concentrations of ethers are far below any threshold where they could pose a possible concern to people’s health. This assessment for MTBE is valid for ETBE and TAME as well.

The EU-Risk assessment for MTBE confirmed a taste and odour threshold of 15 µg/l for MTBE and this limit has been included in water quality regulations in several EU Member States.

Groundwater concentrations (= underground water)
Background concentrations (= surface water e.g. rivers, lakes)