The latest
GASIL makes the following claim with reference to the new rules on blood alcohol concentration and flying:
The human body manufactures its own alcohol, and it is possible for the level of that ‘selfmanufactured’ alcohol to almost reach that 20 milligram level, so it would be prudent for anyone who is subject to the Act to think of the permitted level as equating to no consumed alcohol at all.
I've never heard of such a thing, and would be interested in references to literature that reports the distribution for a sample population of background blood alcohol concentrations in the absence of alcohol consumption.