The main problems could be to be diabetic (test will confuse acetone with alcohol, false positive), to have alive yeast in the intestine (true positive even wit

The main problems could be to be diabetic (test will confuse acetone with alcohol, false positive), to have alive yeast in the intestine (true positive even without drinking, would still be drinking under the influence), or to work in a lab (false positive, normally). You could have a false negative also, but that would be a problem by different reasons. You can request a blood test explicitly any time that you are required to pass the breath analyzer, the problem is that the movement could backfire and not play in your best interest. It will happen if you fail the breath analyzer test by a lot I talking about Europe, the laws in your country can be different, but is obvious that a driver with a tracheotomy should not lose their license just because they have a hole in the neck and are unable to use a breath-analyzer. They can always comply on doing a blood test. Common sense should be applied by the law enforcers.