When you have an ignition interlock installed in your vehicle, you should be told that the only cure for the effects of alcohol is time. Food, coffee, cold showers and fresh air won’t help anyone sober up. Only time can remove alcohol from the system. If you’ve been drinking, wait a certain number of hours until the alcohol has dissipated, and you should be able to blow into the interlock device and start your vehicle.
It could be two things. The most likely is that there was so much alcohol in the system that there wasn’t time for it all to dissipate. There’s no law that says a good night’s sleep will make one sober. If your blood alcohol concentration (BAC) was .20, more than twice the legal limit for drunkenness, it can take fully half a day to get back below .02 or .025, the level at which an interlock will register a “pass.”
The second thing is trickier. Alcohol does not get processed by the body very well during sleep. That means that if you drink right before going to sleep, some of the alcohol might still be unabsorbed when you wake up. You will then start to absorb it. Since it takes a while for blood alcohol to reach its peak, your BAC might actually go up during the morning, even if you haven’t had a drink since the previous night.
So if you are an ignition interlock user, this is how you keep from accidentally failing a morning breath test:
- If you drink at night, leave ample time for the alcohol to leave the system before trying to start your vehicle.
- The more you drink, and the later you drink, the longer it will be until you can pass your breath test and drive your interlock-equipped vehicle.
Having to wait so long after drinking might seem to be an inconvenience, but in fact, the interlock device is just doing its job. When alcohol is in your system, even from the previous night, your faculties are compromised much as it would be if you’ve taken a drink in the past hour. The interlock keeps impaired drivers off the road – and keeps you from getting in trouble with the law.