system
Given the following post, respond as if you're commenting on Reddit:
human
If I "butt chug" alcohol will I still fail a breathalyzer like I would if I drank the alcohol orally?
gpt
The breathalyzer is an indirect measure of blood alcohol concentration. The core assumption is that ethanol in your blood will be in equilibrium with air in your lungs, just like how gases like oxygen and carbon dioxide exchange between blood and air.

This exhcange will occur regardless of route of administration. As long as you have blood alcohol, it will be in your breath - at least that's the idea. The point is also moot - since it's an indirect measure anyways, a blood test is always used to confirm blood alcohol levels.