EDIT:
The law is complicated on this topic and it varies by region. I didn’t think this needed saying when I made the post, but this isnt an end all be all on the topic, it’s just something I found interesting & posted it to c/Today I Learned.
Don’t take legal advice from a Lemmy post. Talk to a lawyer.
The Purpose of Portable Breath Tests
Portable breath tests are commonly used by law enforcement officers to quickly estimate a person’s blood alcohol content (BAC) at the scene of a suspected DUI offense. These handheld devices are designed to provide immediate results, helping officers in their decision-making process during a traffic stop or investigation.
It is essential to understand that a portable breath test is different from the more accurate breathalyzer devices used at police stations or during formal chemical testing. While portable breath tests can provide an initial indication of a person’s intoxication level, they should not be considered as wholly accurate or infallible.
https://rhilllaw.com/blog/2021/03/can-a-portable-breath-test-be-used-in-court/
In Australia, though it might vary from state to state, you can request a blood test. If there’s no booze bus right there in which they’ll take it, you might be able to make the cop go to the pathologist with you within a few hours during which you might dip under the limit if it was borderline. Never heard of anyone actually pulling this stunt, I’m sure it would royally piss off the cop.
In Germany as well. But the blood test actually requires a judge to sign off (unless you do it voluntary).
Just say no to drug tests! Especially if you have time and the cops don’t. They will usually let you go about your day as they would rather keep doing the breathaliser test with people who don’t know that they can just refuse.