As fuel ethers, MTBE, ETBE and TAME are related substances of the same generic family. The large quantity of scientific evidence and of independent official reports shows that they are safe with respect to the environment and health. MTBE, however, has been the focus of most research because it is by far the most widely used at present. The environmental and health impact of MTBE is therefore comparable, with the exception of certain minor variations, with that of ETBE and TAME.

MTBE has recently undergone a full EU risk assessment study for both health and environmental effects. The results were published in the Official Journal of the European Union on 4th December 2001 and the full report is available from the European Chemicals Bureau.

The EU risk assessment on MTBE has been conducted within a very well defined regulatory framework according to EU's Technical Guidance Document (TGD). In this process, both health and environmental effects are evaluated, together with the potential for exposure, in order to assess the overall risk that a substance may present. This process led to a formal decision by the European Union that MTBE is not classified as carcinogen, mutagen or reproductive toxin.

The conclusion of the risk assessment as far as human health is concerned is that risk for consumers are not expected and risk reduction measures already being applied are considered sufficient. Regarding workers exposure, the report mentions concerns for repeated local skin effects for workers involved in maintenance operations and automotive repair, for which the adequate risk reduction measure is the use of the skin protection equipment already used for protection against other gasoline components.

The risk assessment identified a need for specific measures to limit the risks in relation to the aesthetic quality of ground water (taste and odor).  As a follow-up, recommendations to reduce these risks were adopted in December 2001 and published in the Official Journal of the European Union (see above). These proposals are mainly dealing with the construction and operation of petrol underground storage and distribution facilities at service stations with a view to prevent leakage.

The publication in September 2004 of the addendum to the environmental risk assessment for MTBE marks the end of the EU risk assessment process for MTBE. The additional test to assess possible fish avoidance behaviour in presence of MTBE conducted at the request of the European Chemical Bureau concluded that no avoidance behaviour was observed.