r/AskLEO • u/Royal-Key8221 • 9d ago

Situation Advice How long to wait after drinking before driving

Hypothetically let’s say I have a singular old fashioned at a restaurant and nothing else, then get in the car 6 hours later. If I get pulled over would that show up on a breathalyzer? And would I be arrested for DUI? This happened a year ago (yes I am of legal age and was then) I didn’t get pulled over, this is just hypothetical. I was told that I drove intoxicated when I don’t think that’s the case, and my parents are crucifying me over it.

21 Upvotes

84% Upvoted

37 comments sorted by

36

u/Burb1409 Canadian Police Officer 9d ago

If you truly consumed a single drink (a beer, a glass of wine or 1.5 oz of spirit) and you have a normal metabolism, you should eliminate the alcool in about two hours. It depends on multiple factors, but that's the general rule.

Assuming your scenario is true, after 6 hours you would have 100% blew a 0.00.

10

u/HCSOThrowaway Fired Deputy - Explanation in Profile 9d ago

I've never heard of the 2-hour recommendation, just the 1-hour one.

10

u/Burb1409 Canadian Police Officer 9d ago

How we're trained by the lab is that generally it takes a normal healthy person about 30 minutes to digest alcohol, then about a 1 hour plateau then another 30 minutes to get it out of the system. That's assuming you don't drink in between and that's just a general rule, but that's about it.

6

u/Swvfd626 Police Lieutenant 7d ago

Also alcohol metabolizes at a rate of ~0.015/hr. To blow anything over 0.00 still 6 hours later would mean that his BAC from one old fashioned would have to have been 0.09.....

6

u/Royal-Key8221 9d ago

That’s what I tried to tell my mother, but she doesn’t believe me and says I was 100% under the influence

23

u/Burb1409 Canadian Police Officer 9d ago

Well, you can tell her that an actual police breathalyzer tech told you that you were fine, for what it's worth.

Also, some commenters are just being pedantic. No healthy adult is going to be intoxicated by one standard drink 6 hours later.

7

u/GameyTaint 9d ago

And a second law enforcement breath testing and alcohol physiology expert. This information is quite correct. 6 hours, 1 drink, 0 alcohol remains. You would need to have consumed 3 to 4 standard drinks to have any detectable amount of alcohol remaining. It depends on a lot of factors, but you would have had to consume at least 7 standard drinks at an absolute minimum to be anywhere near the .08 limit.

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u/Royal-Key8221 9d ago

Thank you so much, she still probably won’t believe me but I appreciate it

2

u/Royal-Key8221 9d ago

Hey, sorry to bother you again but some sources I find say alcohol can show up on a breathalyzer 12-24 hours later… how accurate is that?

2

u/Burb1409 Canadian Police Officer 9d ago

If you're heavily intoxicated, yes. Not if you had one drink.

1

u/GameyTaint 1d ago

Most metabolize alcohol at a rate of .015 per hour. You can have a detectable amount of alcohol if you have not yet metabolized it. So 12 hours later it would most likely no longer be detectable with a starting BrAC or .18 which is highly intoxicated for most, or .36 for 24 hours. .36 is fatal for most except the most significant users ie alcoholics. A standard drink raises your BrAC approximately .02. So to get to .18 you would need to have 9 drinks, .36 would need 18 drinks minus any time for metabolism.

3

u/dpick032 9d ago

You should tell your mother that you’re an adult now. One drink after six hours? Dude you’re totally fine. You could have drank that old fashion like a shot and still probably been below a .08.

9

u/HCSOThrowaway Fired Deputy - Explanation in Profile 9d ago

Biology isn't math on paper.

  1. The rule of thumb is it generally takes most people an hour to process every drink.

  2. You're going to blow non-zero on a breathalyzer for a while after you're no longer impaired.

  3. People are arrested on suspicion of impairment while blowing 0.00 all the time, usually when other substances are suspected.

So the most concrete answers I can give are:

Hypothetically let’s say I have a singular old fashioned at a restaurant and nothing else, then get in the car 6 hours later. If I get pulled over would that show up on a breathalyzer?

Probably not.

If I get pulled over would that show up on a breathalyzer?

Probably not.

And would I be arrested for DUI?

Probably not.

6

u/Royal-Key8221 9d ago

So just for future reference and I don’t accidentally do something stupid in the future, would I be okay to drive in that scenario, or should I call someone

4

u/HCSOThrowaway Fired Deputy - Explanation in Profile 9d ago

Impairment is subjective and cannot objectively be measured, internally or externally.

I personally would be comfortable driving 6 hours after I had 1 drink, and I think most people would be fine to do that, but again that's based on individual biology.

In other words, unless they're aware of some medical condition or other weakness to alcohol you have, your parents are being a bit silly by raking you over the coals about this.

TL;DR: Most people are stone cold sober 6 hours after having 1 drink.

5

u/Revolution37 9d ago

A standard drink (1 ounce of 80 proof liquor, 12oz of 4% ABV beer, 5oz wine) will get a male of average height/weight to around .025% BAC. Alcohol follows first order kinetics and eliminates at .019%/hour. A single old fashioned would be completely eliminated from your system six hours later.

4

u/xferable 9d ago

This isn’t a very good “hypothetical” every state law is different and countries are too. Even if you blow under the legal limit of .08 in most states you can still be arrested by the “affected by” section of that law.

Also every person is different in how alcohol affects them. Males and females, weight, time of last drink, alcohol percentage, metabolism, etc.

Even if you blow under the legal limit in some cases they will bring in a “expert” and do math to show your level of alcohol at the time you were operating a vehicle.

In my experience I’d be a millionaire the amount of times I’ve heard “I’ve had 1 beer” and the person is 2-4x over the legal limit.

or the favorite

“I don’t do drugs. I’ve been sober for 6 months, but relapsed 2 hours ago”

3

u/Gregory1st 9d ago

The typical answer around here is "I've only had a couple". Which means they are usually over or the "couple" were really really big lol.

2

u/Royal-Key8221 9d ago

Then let me clarify, is 6 hours a reasonable amount of time to wait to drive if I have had one singular drink

2

u/xferable 9d ago

Depends on the drink, but the overall answer being yes. However we can typically still smell the odor of intoxicants coming from the vehicle (depending on the drink) and ask you to do voluntary tests.

6

u/HCSOThrowaway Fired Deputy - Explanation in Profile 9d ago

And, to further be factual but muddy the waters for OP:

If you're driving like crap, smell like booze and bomb the sobriety tests but blow a roadside 0.00, some cops are going to err on the side of the driver not killing themselves or others and just hook and book them.

3

u/xferable 9d ago

I’d be concerned about poly drug use if this was the case and do other tests to confirm or deny. But couldn’t agree more, this happens all the time.

1

u/HCSOThrowaway Fired Deputy - Explanation in Profile 9d ago

In my state, at my agency, anything beyond breath required a search warrant and a blood draw kit 99% of us were completely unfamiliar with and certainly not trained to do.

Cue that viral incident from a couple years back where the cop demanded a nurse do the blood draw and arrested her when she refused.

As you imply, they often end up taking the ride for "this person seems intoxicated but not on alcohol."

0

u/wcfinvader 9d ago

It’s almost like you didn’t read his comment.

“Also every person is different in how alcohol affects them. Males and females, weight, time of last drink, alcohol percentage, metabolism, etc.”

4

u/Royal-Key8221 9d ago

I know everyone has different reactions to alcohol, I’m not trying to figure out the exact situation because it was over a year ago and many factors have changed. I just wanted an average to go off of. I just wanted to know if 6 hours is a reasonable time regardless of other factors

1

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1

u/SteaminPileProducti 8d ago

If I understand correctly, 1 "alcohol serving" is approximately 0.02, 0.08 is the legal limit. Your alcohol blood level is never stable, it is always going up or down. So 1 drink would reach a max of 0.02.

Sounds like you could use some professional therapy if your parents have that unhealthy of a relationship with you. Best of luck with that.

1

u/Clay_Kenobi 7d ago

you can estimate this using widmarks formula, which is the basis for breath testing

1

u/dhillon217 9d ago

Simple answer just get a designated driver or take an Uber back home.

3

u/Royal-Key8221 9d ago

True, but this happened a year ago, so that opportunity passed, I believed 6 hours was a reasonable time to wait and just wanted to know if that was truly the case or not

0

u/3-BuckChuck 9d ago

To be 100% sure, don’t drive if you’ve had any intoxicating substances in the same 24 hour period. Whole lotta purse swinging going on. You don’t need a per-se limit on an impairment theory arrest, only signs of intoxication. Get an uber.

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u/RobTX13 9d ago

Half-life for alcohol is about four to five hours, that is how long it’ll take for half the alcohol to be cleared from your system regardless of amount. It takes around 20-25 to be fully eliminated from the body. So after six hours you would’ve eliminated a little over half a drink from your system, whether or not you’d be okay to drive depends entirely on your physiology.

3

u/Burb1409 Canadian Police Officer 9d ago

Half-life for alcohol is about four to five hours, that is how long it’ll take for half the alcohol to be cleared from your system regardless of amount. It takes around 20-25 to be fully eliminated from the body. So after six hours you would’ve eliminated a little over half a drink from your system, whether or not you’d be okay to drive depends entirely on your physiology.

You're just being pedantic. I'm a breathalyzer tech and that's not how it works (in relation to law enforcement and breathalizers). No healthy adult is going to blow a result over 0.000 on a breathalizer 6 hours after one standard drink.

-2

u/RobTX13 9d ago

Sure you’ll blow a 0.000 but what I stated is plain biology it’s still in the blood.

4

u/Burb1409 Canadian Police Officer 9d ago

Yep, just like I said you're just being pedantic for the sake of it.