Can a person fail a EtG test after 80hrs if not why advertise detection of up to 5 d

Sure they can fail... and some people do fail all the time. That number is just an average... if you are under prohibition from consumption... then you aren't supposed to use it period. If you defy orders and fail, its completely upon you for violating the restriction. Hopefully they will find a way of detecting ANY use over a far longer period. Or streamline it enough they can test everyone subject far more often to catch more people trying to game the system between random tests.

I am not aware of any 5 day claim but 80 hours is what I see. Sure you can fail, people who do not drink can fail too, its not fool proof.

I have heard of people who've failed after 5 or more days. The detection time for a given amount of alcohol will fall on a bell curve. Given 1000 people, there will always be 2 or 3 who've evacuated all the EtG/EtS after 10 hours and 2 or 3 who'll test positive after 5+ days. The majority will be in 2 or so standard deviations comprising of about 90% of the people.

There will always be the cases where people are clean early or test positive late. The majority will fall in the 60-80 hr range.

Why chance it though, be sober.