http://www.eurekalert.org/pub_releases/2007-02/ns-utd021407.php
"Skipper is, however, critical of health boards and agencies in some
states that he says have been automatically sacking people who fail
the EtG test without using other tests to confirm its findings. In the
three to four years that the test has been commercially available in
the US, more than 100 nurses in recovery from alcoholism have
complained of losing their jobs after testing positive despite, they
say, not drinking. Blood tests for a second metabolite such as
phosphatidyl ethanol would be far less likely to give a false
positive, as this substance appears only after large amounts of
alcohol have been consumed, but these tests are more expensive."
"Using the EtG test alone, the risk of false positives remains,
particularly in hospital wards, where nurses and doctors routinely use
soaps containing ethanol. "In intensive care units, nurses and doctors
apply it every 5 minutes," Skipper says. He has shown that the test
could give a positive result in ward staff who have simply breathed
vapour in. Even bystanders can test positive. Both Skipper and the
test's creator, Friedrich Wurst of the psychiatric clinic at the
University of Basel, Switzerland, say that there is not yet an agreed
threshold concentration that can be used to separate people who have
been drinking from those exposed to alcohol from other sources. Below
1000 nanograms of EtG per millilitre of urine is probably "innocent",
and above 5000 booze is almost certainly to blame. In between there is
a "question zone", Skipper says."
You're not paranoid if they really are out to get you.
-bdbafh