Fuel Ethers Risk Assessments
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Introduction
MTBE
TAME and ETBE
TAEE
What happens now with REACH implemented?
In conclusion
Introduction
In 1993 the EU-Existing substances regulation 793/93 came into force. During its lifetime Risk Assessments were conducted on about 140 priority substances within a well defined regulatory framework. In a Risk Assessment the toxicity thresholds from hazard assessments are compared with the expected exposure levels. No risk means therefore that the toxicity threshold is well above the expected exposure level.
MTBE belongs in the top 2% of most tested chemical substances and is one of about 140 substances that have been subjected to a comprehensive EU risk assessment. MTBE (and TAME) were among the priority substances primarily because of their high volumes and widespread use in gasoline.
The EU Risk Assessment Report (EU-RAR) for MTBE clearly shows that risks for consumers are not expected as risk reduction measures already being applied are considered as sufficient. For workers it is essential to protect against repeated skin exposure to avoid local skin effects such as defatting and cracking.
The EU-RAR identified a need for specific measures to limit the risks in relation to the aesthetic quality of ground water. The measures mainly deal with the construction and operation of petrol underground storage tanks and distribution at service stations with a view to preventing leakage. The taste and odour threshold of 15 µg/l has been included in water quality regulations in several EU Member States.
The assessment concluded that 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 International Agency on Research on Cancer (IARC) concluded in 1998 that there was no evidence to justify classifying MTBE as a human carcinogen. A number of other well-respected organisations have reached a similar conclusion. The WHO International Programme on Chemical Safety (IPCS) concluded it was unlikely that MTBE alone could cause adverse acute health effects in the general population under common exposure conditions.
Due to its similar chemical structure, and from a comparison of the existing toxicity data, the Finnish Competent Authority concluded that the possible risks from use of TAME and ETBE were similar to those of MTBE. Furthermore a report on the required risk reduction measurements was prepared by the relevant Committee of the EU member states which demanded a European standard for underground storage tanks and mandatory requirements for service stations. EFOA's MTBE Resource Guide was designed to educate and inform people on the potential groundwater risks and how to deal with them.
As a new substance (= any chemical produced or used after September 18, 1981), TAEE is subject to a full risk assessment outside the REACH timeline.
What happens now with REACH implemented?
As REACH, the new EC chemical regulation, is replacing the existing substances regulation and other EC regulations and directives for safe handling of chemicals, producers have to provide by the end of November 2010 an update of the EU-RAR within their REACH registrations including risk assessment and operational conditions for a safe use.
The hazards and risks of fuel ethers have been comprehensively assessed firstly in the EU Risk Assessments and then with an update to meet the standard demanded by REACH.
Further reading
Fuel Ethers and Groundwater
Useful links
Ecetoc Risk Assessment for MTBE