Human exposure to MTBE has become widespread. Under unique circumstances, exposures can be quite high. Because MTBE readily partitions from the blood into the breath, there is the potential for interference on breath alcohol analyzers, says Timothy J. Buckley, assistant professor at the Johns Hopkins Bloomberg School of Public Health. We studied this and our results showed that MTBE does present a positive interference on the older type analyzers. Workers like gas station attendants and auto mechanics may receive sufficient levels of MTBE to trigger a .10 reading on certain breath-alcohol analyzers, which is one legal standard for intoxication, but only in combination with drinking alcohol. MTBE exposure on its own is not enough to trigger a false positive reading of .10, explains Dr. Buckley.
New Jersey state officials first raised the question of whether MTBE exposure could interfere with breath-alcohol analyzer when they were challenged in a court case in 1995. Dr. Buckley and his colleagues compared the Breathalyzer with the Alcotest detector. Both breath-alcohol analyzers are commonly used by police officers in United States. The Breathalyzer was developed in the 1950s and uses a visible light detector to determine the presence of alcohol in the breath, while the newer Alcotest uses electrochemical and infrared absorption sensors to detect alcohol levels. Various breath mixtures of MTBE and MTBE mixed with alcohol were simulated in a laboratory and run through both machines.
Contact: Tim Parsons or Ming Tai
Johns Hopkins University Bloomberg School of Public Health