Alcohol testing options: breath, EtG and what each one tells you

Breath alcohol testing

A breath test measures alcohol in the body at the moment of the test. It is fast, non-invasive and performed on site. DOT alcohol screening may be performed using an approved breath or saliva screening device. A DOT confirmation test is performed by breath using an approved evidential breath testing device. A screening result of 0.02 or higher is followed by a 15-minute wait and a confirmation test, which produces the result of record.

Breath testing answers questions about the present: post-accident, reasonable suspicion, random alcohol testing and return-to-duty. Its limit is time. Alcohol clears the body within hours, so a late breath test tells you little. That is why post-accident and reasonable suspicion alcohol tests are done first and fast.

EtG testing

Ethyl glucuronide (EtG) is a substance the body produces after alcohol is consumed. EtG urine testing reaches back about 80 hours, so it can show recent drinking even when the person is completely sober at the time of collection.

EtG is the tool for abstinence monitoring: court and probation conditions, custody arrangements, treatment and recovery programs and zero-tolerance workplace policies. It is a laboratory test collected under chain of custody. EtG is not a DOT alcohol test.

Programs set cutoffs to tell drinking apart from incidental exposure, such as hand sanitizer, and laboratories often report a second marker, ethyl sulfate (EtS), to help interpret results.

Which test fits the situation

• Post-accidentBreath, as soon as possible.
• Reasonable suspicionBreath, immediately.
• Random testing (DOT or company policy)Breath, timed around duty.
• Court, probation or custody abstinence conditionsEtG.
• Treatment or recovery monitoringEtG, sometimes with periodic breath tests.
• A family concern about recent drinkingEtG, or breath if the concern is about right now.

General education, not legal or medical advice. DOT alcohol testing follows 49 CFR Part 40. Non-DOT programs follow their written policy or the ordering party’s requirements.