21 March 2007
Blame it on the Worcestershire sauce
You may be on a low-calorie diet, but the machine says you've been drinking:
Researchers at Sweden's Karolinska University Hospital were approached by a 59-year old non-drinker after he registered positive for alcohol when blowing into an in-car ignition interlocking device that would not allow him to drive. As a glider pilot who supervised private aviation, the man had been surprised and upset about the positive result, which occurred while he was undergoing a weight loss program involving a very low calorie diet.
Researchers found the positive test to be the result of a chemical reaction that took place when fat was broken down at a fast rate. When this happened, ketone bodies (acetone, acetoacetate and beta-hydroxybutyrate) were produced, which could then be converted to a secondary alcohol known as isopropanol, said the lead researcher, Wayne Jones, who is also on Sweden's National Board of Forensic Medicine.
At least in Australia, this phenomenon won't get you busted:
Edward Ogden, clinical forensic scientist and senior research fellow at Melbourne's Swinburne University, said it was possible that sober people could blow a false-positive test, however they would not be charged with drunk driving. Alcohol ignition interlock devices and roadside random breath testing units measure alcohol on the breath using fuel cells, which cannot distinguish between ethanol and isopropanol.
"But with any random breath test, the police would then invite you to the booze bus for a second test using an evidential instrument which measures the presence of alcohol on the breath in three different ways, including the use of infra-red at two different wavelengths," Dr Ogden said.
The real problem, apparently, is for people with the interlock devices, which have yet to be put to any significant use here in the States.
(Via Autoblog.)Posted at 4:00 PM to Driver's Seat