Where the 80-hour label comes from
EtG lasts longer than ethanol and has been detected several days after substantial drinking in some settings. That capability was compressed into the memorable phrase '80-hour test,' even though published sensitivity varies by exposure and cutoff.
Detection capability is not guaranteed sensitivity
A test may detect some high-exposure samples at 80 hours while missing many lighter exposures earlier. Research reporting percentages across groups is more informative than a single maximum number.
How the cutoff changes the claim
At 100 ng/mL, lower residual EtG can be reported. At 500 ng/mL, the same sample may already be negative. Any statement about an 80-hour window that omits the cutoff is incomplete.
A better way to use detection windows
Think in probability bands: early periods are more consistently detectable; middle periods vary with dose and threshold; late periods are increasingly uncertain. Only an actual test can determine whether a specific sample is above its cutoff.
Frequently asked questions
Will one drink show up after 80 hours?+
That would be unlikely in many circumstances, but no online source can guarantee an individual result. Cutoff, sample concentration, and biology still matter.
Evidence and limitations
This guide summarizes primary research and public-health guidance. Group-level findings cannot predict one person's result.