Alcohol testing comes in two very different forms that are often confused. One tells you whether someone is under the influence now. The other tells you whether they have been drinking recently. Choosing the wrong one gives you an answer to a question you did not ask.
Breath testing
A breath test measures the concentration of alcohol in the body at the moment of the test. It is fast, non-invasive and performed on-site. In a DOT setting it has two distinct stages. Screening may use an approved alcohol screening device (ASD, breath or saliva) or an evidential breath testing device (EBT) where Part 40 allows. A screening result of 0.020 or greater requires confirmation, which must be performed on an approved EBT that meets Part 40 requirements, after the required waiting period.
Breath is the method for any question about current impairment: post-accident, reasonable suspicion, random alcohol testing, and return-to-duty.
The limit is time. Alcohol clears the body within hours, so a breath test performed late tells you little. That is why post-accident and reasonable suspicion alcohol tests are done first and fast.
EtG testing
Ethyl glucuronide is a metabolite the body produces after alcohol is consumed. It remains detectable in urine for days, and in hair for months. An EtG test therefore answers “has this person consumed alcohol recently,” even if they are completely sober at the time of collection.
EtG is the tool for abstinence monitoring: court and probation conditions, custody arrangements, treatment and licensing programs. It is a Non-DOT laboratory test and is not used for DOT alcohol testing.
Programs set cutoffs to distinguish drinking from incidental exposure (hand sanitizer, some medications and foods), and laboratories often report a second marker, EtS, to help interpret results.
Which one fits
| Situation | Use |
|---|---|
| Post-accident | Breath, as soon as possible |
| Reasonable suspicion | Breath, immediately |
| Random (DOT or policy) | Breath, timed around duty |
| Court, probation or custody abstinence condition | EtG (urine or hair) |
| Treatment or recovery monitoring | EtG, sometimes with periodic breath |
| Family concern about recent drinking | EtG, or breath if the concern is right now |
What about blood or urine alcohol?
Blood alcohol is precise but invasive and is used mainly in medical and law-enforcement settings. A plain urine alcohol test measures alcohol itself, which clears quickly and can be affected by fermentation in the sample; EtG is generally the better urine-based choice for recent-use questions. Neither is used for DOT alcohol testing.
Both tests come to your location. See breath alcohol testing and EtG testing, or call 1-800-539-4934.