DOT Alcohol Test 0.02 vs 0.04: What Each Result Actually Does (2026)

Published September 18, 2026 | TruckerNavi Inc | 21 min read

By the TruckerNavi compliance team, led by Dmitry Borovoy, a New Jersey-licensed insurance producer and author of Safety Manager: From Zero to Expert.

The short answer: 0.02 and 0.04 are not two points on one scale of trouble. They are two different legal events with two different paperwork trails.

• A confirmed result of 0.02 or greater but less than 0.04 stops the driver from performing safety-sensitive functions until the start of the next regularly scheduled duty period, and not less than 24 hours after the test was administered. That is the whole federal consequence. Under 49 CFR 382.505(a) it is filed as "other alcohol-related conduct", not as a prohibited-conduct violation. It is not reported to the Clearinghouse. No substance abuse professional, no return-to-duty test.
• A confirmed result of 0.04 or greater violates 49 CFR 382.201. The employer removes the driver immediately under 40.23(c), reports it to the Clearinghouse by the close of the third business day under 382.705(b)(1)(i), and the driver stays out of the seat until the return-to-duty process of 49 CFR Part 40 Subpart O is finished, per 382.217(b).

One more number matters before either of those. 0.02 is the point where a screening test stops being the end of the story. Below 0.02 on the screen, the test is over. At 0.02 or higher on the screen, nothing has been decided yet, because only a confirmation test on an evidential breath testing device carries consequences. Everything below is sourced to the rule text in 49 CFR Part 40 and Part 382. This is a walkthrough of the procedure, not legal or medical advice.

What exactly is a "0.04" in the regulation?

It is not a percentage of what you drank and it is not a blood measurement. 49 CFR 382.107 defines alcohol concentration as the alcohol in a volume of breath expressed in terms of grams of alcohol per 210 liters of breath, as indicated by an evidential breath test under Part 382.

Two things follow from that one sentence:

• The number is a breath number. 49 CFR 40.277 is blunt: other types of alcohol tests, blood and urine among them, are not authorized under Part 40. Saliva or breath for screening, breath only for confirmation.
• Only the evidential number counts. A saliva stick reading is a screening result. It routes the driver to a confirmation test. It never becomes the official concentration.

Note also what 0.04 is not: it is not the state DUI limit, which is 0.08 in most states for a passenger-car driver. The DOT employer program sits far below that, and roadside enforcement under 49 CFR 392.5 sits lower still, which is the section most owners have never read.

What happens at 0.02 to 0.039, step by step?

Assume the confirmation test on the EBT prints 0.031. The entire sequence is shorter than people expect.

1. The BAT notifies the designated employer representative immediately. 40.255(a)(5)(i) requires immediate notification of any result of 0.02 or greater, by a means that ensures the DER actually receives it, and expressly not through a C/TPA or other service agent.
2. The employer removes the driver temporarily. 40.23(c) uses that exact word for the 0.02 to 0.039 band, in contrast to the immediate removal it requires at 0.04.
3. The clock is the longer of two things. 382.505(a): no safety-sensitive functions until the start of the driver's next regularly scheduled duty period, but not less than 24 hours following administration of the test. If the next shift starts in 10 hours, the driver still waits 24. If the next shift is four days out, the driver waits four days.
4. Then the driver goes back to work. No SAP, no return-to-duty test, no follow-up testing plan. Those belong to the 0.04 track.
5. Nothing goes to the Clearinghouse. The list in 382.705(b)(1) contains exactly one reportable positive alcohol threshold, and it is 0.04 or greater. The other alcohol entries on that list are a negative return-to-duty result under (b)(1)(ii) and a refusal to take an alcohol test under (b)(1)(iii).

382.505(b) then draws a fence around the whole thing: except for that removal, no employer shall take any action under Part 382 against a driver based solely on test results showing an alcohol concentration less than 0.04. The same paragraph preserves the employer's own authority: a company with a stricter internal policy, acting independently of Part 382 and consistent with law, may still act. That is a company decision and a company liability, and it belongs in the written policy handed to drivers rather than being invented after a result comes back.

What happens at 0.04 or greater?

Now it is a violation of a prohibition, and the machinery is completely different.

• 382.201 bars the driver from reporting for duty or remaining on duty requiring safety-sensitive functions with an alcohol concentration of 0.04 or greater, and bars the employer with knowledge from permitting it.
• 40.23(c) requires immediate removal on receipt of the result, without waiting for the written report.
• 382.705(b)(1)(i) requires the employer to report the confirmation result of 0.04 or greater to the Clearinghouse by the close of the third business day after obtaining it, with the reason for the test, the driver's CDL number and state, the employer's USDOT number and the dates.
• 382.217(b) and 382.503 keep the driver out of safety-sensitive work until the return-to-duty requirements of 49 CFR Part 40 Subpart O are met.
• 382.501 removes the driver from safety-sensitive functions for any Subpart B conduct, including this one.

One detail carriers miss: the reporting duty may be delegated to a consortium or third-party administrator under 382.705(c), but the employer retains ultimate responsibility for compliance. Handing the account to a C/TPA does not hand over the finding in an audit. The only exception is written into 382.705(c) itself: the employer does not retain responsibility where the C/TPA is designated to comply with employer requirements under 382.705(b)(6), that is, the owner-operator who reports his own testing.

Every result and what it does: the table

This is the working document. Match the number, know the consequence, know whether a federal record is created.

Screening test versus confirmation test: what actually changes?

The two tests are not the same procedure run twice. They differ in the device, the operator, the timing rules and the legal weight.

The screening test is defined in 382.107 as an analytical procedure to determine whether an employee may have a prohibited concentration of alcohol in a breath or saliva specimen. Under 40.229 it can run on an alcohol screening device (ASD) from the approved list or on an EBT, and the same sentence draws a hard line: an ASD can be used only for screening tests and must not be used for confirmation tests. Procedurally it is short. For a breath screen, 40.243 has the technician open a sealed mouthpiece in view of the employee and instruct a steady, forceful blow for at least six seconds or until the device signals enough breath. For a saliva ASD, 40.245(a)(8) requires the result to be read no sooner than the manufacturer allows and in all cases within 15 minutes of the test. Reading it early or late is a fatal flaw under 40.267(a)(1), and the test dies.

The confirmation test is where the number becomes real, so the rule demands a machine that produces evidence rather than a reading. 49 CFR 40.231 permits only EBTs from the approved list that can do all six of the following:

1. Print a triplicate result, or three consecutive identical copies of the result.
2. Assign a unique number to each completed test, readable by the BAT and the employee before the test and printed on every copy.
3. Print the manufacturer's name for the device, its serial number and the time of the test on each copy.
4. Distinguish alcohol from acetone at the 0.02 level. Acetone is the reason this line exists: it appears in breath in some metabolic states, and a cruder sensor can read it as alcohol.
5. Test an air blank.
6. Perform an external calibration check.

Then 40.253 makes the BAT use those capabilities in front of the employee: an air blank before the test that must read 0.00, a second air blank if the first is higher and the EBT out of service entirely if the second is also above 0.00; a new sealed mouthpiece opened in view; the unique test number read by both; a blow of at least six seconds; and the printed result shown, then attached to the Alcohol Testing Form with tamper-evident tape or a tamper-evident label. There is a quiet retroactive rule in 40.267(c)(5) as well: if the EBT's next external calibration check comes back outside the tolerance in the quality assurance plan, every result of 0.02 or above obtained on that device since the last valid check is cancelled. A carrier that logs which device tested which driver on which day is the carrier that can act on that.

What is the 15-minute wait, and what is the 30-minute limit?

The most misunderstood pair of numbers in alcohol testing, and the source of most cancelled tests.

The reason for the wait is written into the script the BAT must read. Under 40.251(a)(2) the technician must tell the employee not to eat, drink, put anything into the mouth or belch, must explain that the purpose is to prevent an accumulation of mouth alcohol from leading to an artificially high reading, and must add that the confirmation test happens at the end of the waiting period even if the instructions were not followed. Someone has to observe the employee during the wait: the BAT, another BAT or STT, or an employer representative. If the confirmation happens at a different site, the transit time counts toward the waiting period when the person who ran the screening gave those instructions, per 40.251(a)(1)(i), and the employee must not drive there. And if more than 30 minutes have passed, 40.251(e) forbids starting over with a new screening test: you begin the confirmation procedures, note the elapsed time and the reason on the "Remarks" line, and proceed.

Who is a BAT, who is an STT, and how do their roles differ?

Under 49 CFR 40.211(a), screening test technicians and breath alcohol technicians meeting the training requirements of Subpart J are the only people authorized to conduct DOT alcohol tests. Not a nurse who happens to be on site, not a safety manager with a device in a desk drawer, not a dispatcher.

Because an STT cannot confirm, a screening result of 0.02 or higher taken by an STT has to be handed off. 40.247(b)(2) covers it: the STT directs the employee to the confirmation test, signs and dates Step 3, and gives the employee Copy 2 of the ATF, after which the waiting-period and observed-transit instructions apply. The training itself is not a certificate you buy once: 40.213(b) requires qualification training following the DOT Model BAT or STT Course or an equivalent, taught by an instructor who has regularly conducted DOT alcohol tests in that role for at least a year, has trained in that role for a year, or has completed a train-the-trainer course.

Can a supervisor or a police officer perform the test?

Two separate answers, both narrower than people assume.

A supervisor: almost never. 40.211(c) says that as a BAT- or STT-qualified immediate supervisor of a particular employee, you may not act as the STT or BAT when that employee is tested, unless no other technician is available and the DOT agency rules do not prohibit it. For reasonable suspicion testing specifically, 382.307(c) is absolute: the person who makes the determination that reasonable suspicion exists shall not conduct the alcohol test of the driver. One person does not both decide and measure. How that determination is properly made and documented is covered separately in supervisor drug and alcohol training.

A police officer: yes, in a defined way. 40.213(h)(2) deems law enforcement officers certified by a state or local government to conduct breath alcohol testing to be qualified as BATs without the Part 40 training, provided the officer was certified by that government to use the specific EBT or ASD used for the test. Separately, 382.303(g)(1) lets the results of a breath or blood test conducted by federal, state or local law enforcement with independent authority satisfy the post-accident testing requirement, if the test conformed to the applicable requirements and the employer actually obtains the results. That last clause is where carriers lose: the test happened, nobody chased the paperwork, and the file shows no post-accident test.

Who has to be told about the result, and on what form is it written?

A number that reaches the wrong person late is a removal that did not happen on time. The rule is specific about both the paper and the recipient.

The form. 40.225(a) requires the DOT Alcohol Testing Form (ATF) for every DOT alcohol test, and it must be a three-part carbonless manifold form, reproduced in appendix I to Part 40. Copy 2 belongs to the employee: when a screening result of 0.02 or higher is handed off to another technician, 40.247(b)(2) has the STT sign Step 3 and give that copy over. Before any of this, 40.241(c) makes the technician see a photo ID issued by the employer or by a government; faxes and photocopies are not acceptable. Using a non-DOT form is a correctable flaw rather than a fatal one, but 40.271(b)(2) demands a written certification the same business day; using the ATF for a non-DOT test is separately prohibited by 40.227(a).

The recipient. The DER is not a role you can outsource. 382.107 defines the designated employer representative as an individual authorized to take immediate action to remove employees from safety-sensitive duties, and adds two hard limits: the individual must be an employee of the company, and service agents cannot serve as DERs. 40.215 puts the matching duty on the carrier, which must give every BAT and STT the DER's name and telephone number. Then 40.255(a)(5)(i) closes the loop for any result of 0.02 or greater.

Registration and query mechanics on the database side are a separate exercise: see FMCSA Clearinghouse registration and the annual query process.

What if the driver cannot blow, or the site has only a saliva device?

Three failure modes have their own written procedures, and each of them ends at the DER rather than at a verdict.

Not enough saliva. 40.263(a)(1) has the STT run a new screening test with a new device. If the employee refuses to attempt that new test, testing stops, the fact goes on the "Remarks" line, the DER is told immediately and it is a refusal. If the employee tries and still cannot produce enough saliva, 40.263(b) makes the DER arrange a test on an EBT or other breath device.

Not enough breath. 40.265(b) has the technician explain the technique and let the employee try again; refusing to attempt is a refusal to test. When the attempts fail, 40.265(c) requires the employer to direct the employee to obtain within five days an evaluation by a licensed physician acceptable to the employer. The physician reports to the DER directly, never through a C/TPA, and picks one of exactly two conclusions: a medical condition could with a high degree of probability have precluded a sufficient breath, and the test is cancelled; or there is no adequate basis for that finding, and it is a refusal under 40.261(a)(4). 40.265(c)(1)(iv)(C) names what does not qualify: unsupported assertions of "situational anxiety" or hyperventilation.

Only an ASD on site. An ASD screens and never confirms (40.229). At 0.02 or higher the employee goes to an EBT, observed, and 40.247(b)(3)(vii) forbids letting the employee drive there; the transit time counts toward the 15 minutes under 40.251(a)(1)(i). If the saliva device breaks or fails to activate on the repeat attempt, 40.245(a)(6)(vi) sends the employee straight to an EBT for a new screening test. And if the EBT itself fails an external calibration check, 40.233(c)(3) takes it out of service until it is repaired and passes one.

When can a driver be alcohol tested at all?

Alcohol testing is time-bound in a way drug testing is not. 382.305(m) is the governing sentence: a driver shall only be tested for alcohol while performing safety-sensitive functions, just before performing them, or just after having ceased performing them. A random alcohol selection cannot be executed on a driver at home on a day off, and 382.307(d) applies the same window to reasonable suspicion. Pre-employment alcohol testing is optional under 382.301(d), but a carrier that chooses it must test every covered employee after a contingent offer and may not let a driver start unless the result is below 0.04. For 2026 the FMCSA random alcohol rate is 10 percent; how the pool is built, counted and documented is the subject of random testing rates and how the pool actually works.

There is also a rule for the case where no test happens at all. Under 382.307(e)(2), even without a reasonable suspicion alcohol test, a driver who is under the influence of or impaired by alcohol, as shown by behavioral, speech and performance indicators, may not perform safety-sensitive functions until either an alcohol test measures less than 0.02 or 24 hours have elapsed since the determination. Two paperwork clocks sit next to it. 382.307(a) requires the determination itself to rest on specific, contemporaneous, articulable observations of appearance, behavior, speech or body odors. 382.307(e)(1) then mirrors the post-accident timing: if the reasonable suspicion alcohol test is not administered within two hours of the determination, the employer files a record saying why, and if it is not administered within eight hours, the employer stops trying and states the reasons. 382.307(f) adds a written record of the observations, signed by the supervisor who made them, within 24 hours of the behavior or before the results are released, whichever comes first.

What about drinking before the shift, on the shift, and after a crash?

Three separate prohibitions, and each is a violation with no test required if the employer has actual knowledge.

• Four hours before. 382.207: no driver shall perform safety-sensitive functions within four hours after using alcohol, and no employer with actual knowledge may permit it.
• During. 382.205: no alcohol use while performing safety-sensitive functions. Remember how wide "safety-sensitive function" is under 382.107: waiting to be dispatched unless relieved from duty, inspecting or servicing the vehicle, all time at the driving controls, all time in or upon the CMV other than resting in a sleeper berth, loading and unloading or attending a vehicle being loaded, and all time attending a disabled vehicle.
• Eight hours after an accident. 382.209: a driver required to take a post-accident alcohol test may not use alcohol for eight hours following the accident, or until undergoing the post-accident alcohol test, whichever occurs first. The point is evidentiary: a drink after the crash makes the test meaningless, so the rule treats the drink itself as the violation. 382.303(e) adds that the driver must remain readily available for testing or may be deemed to have refused.

All three, once the employer has actual knowledge, are reported to the Clearinghouse within three business days under 382.705(b)(4), together with the date knowledge was obtained, witnesses, a description and the supporting evidence. Actual knowledge is defined in 382.107 as the employer's direct observation of the use, information from a previous employer, a traffic citation for driving a CMV while under the influence, or the employee's admission. It expressly does not include observing behavior or physical characteristics, which is the trigger for reasonable suspicion testing instead.

One definition catches people out here. 382.107 defines alcohol use as the drinking or swallowing of any beverage, liquid mixture or preparation, including any medication, containing alcohol. An alcohol-based cough syrup swallowed two hours before a shift is alcohol use inside the four-hour window of 382.207, whatever the reason for taking it. Mouthwash is a different problem: rinsing is not swallowing, but it leaves mouth alcohol, which is exactly what the 15-minute waiting period of 40.251(a) is designed to clear before the confirmation test.

What does roadside enforcement do, and why is it a lower threshold?

The employer testing program and roadside enforcement are two different systems, and the roadside threshold is lower than 0.02. 49 CFR 392.5(a)(2) prohibits using alcohol, being under the influence, or having any measured alcohol concentration or detected presence of alcohol, while on duty or operating or in physical control of a CMV. 392.5(a)(1) adds the same four-hour pre-duty window as 382.207, and 392.5(a)(3) prohibits possessing wine, beer or distilled spirits on duty, with narrow exceptions for manifested shipments and bus passengers; the wine it names starts at one-half of one percent alcohol by volume, and beer and distilled spirits are the Internal Revenue Code definitions the rule cites. 392.5(b)(2) reaches the carrier as well: no motor carrier may require or permit a driver to be on duty or operate a CMV if, by general appearance or conduct or other substantiating evidence, the driver appears to have used alcohol within the preceding four hours. That is a judgment call with no number attached to it.

The consequence is in 392.5(c): a driver found in violation shall be placed out of service immediately for a period of 24 hours, starting when the order is issued. 392.5(d) then puts two duties on the driver: report the order to the employer within 24 hours, and report it to the state official designated by the licensing state within 30 days, unless the driver requests a review, in which case the 30 days run from an affirmation of the order. 392.5(e) gives a 10-day window to petition for review in writing.

Keep the two tracks apart when you file the paperwork. A 24-hour out-of-service order under 392.5 is an enforcement action recorded on an inspection report. It is not by itself a Part 382 test result and not by itself a Clearinghouse entry. What can turn a roadside event into a Clearinghouse entry is the actual-knowledge route: a citation for driving a CMV while under the influence meets the 382.107 definition, and the employer then reports the underlying 382.205 or 382.207 violation. The carrier side of a crash, including which occurrences require a test at all, is in post-accident testing rules.

What cancels a test, and what counts as a refusal?

40.267 calls the killers fatal flaws, and a cancelled test then means nothing in either direction. The ones that touch the thresholds directly: a confirmation run before the minimum 15-minute waiting period elapses; no air blank before the confirmation test, or an air blank that does not read 0.00; the EBT does not print the result; the test number or concentration on the display does not match the printout; a saliva or breath tube ASD read too early or too late, one that failed to activate, or a device used past its expiration date; and the out-of-tolerance calibration check that retroactively cancels every 0.02 or above since the last valid check. 40.269 adds three correctable flaws, fixable by a signed written statement under 40.271: the technician did not sign the ATF, did not note that the employee failed to sign after the result, or used a non-DOT form. Under 40.273 a cancelled test is neither positive nor negative, carries none of the consequences of a 0.02 or greater result, does not count toward the minimum random testing rate, and gives no basis for a non-DOT test instead; whoever determines the cancellation informs the DER within 48 hours.

A refusal is the opposite: it carries the same consequences as a 0.04 result, meaning removal, a Clearinghouse report and the return-to-duty process. 40.261(a) lists the ways an employee refuses an alcohol test, and one of them is the distinction that costs drivers jobs unnecessarily. Refusing to sign the certification at Step 2 of the ATF, before the test, is a refusal. Refusing to sign Step 4, after a result of 0.02 or higher, is not. 40.255(a)(3) has the BAT note it on the "Remarks" line and move on, in the rule's own words, "this is not considered a refusal to test", and 40.275(b) adds that the missing Step 4 signature does not cancel the test either. Two more boundaries: under 40.261(c)(2) the BAT or STT does not make the final decision about whether conduct was a refusal, because the employer has a non-delegable duty to decide; and under 40.261(d) refusing a non-DOT test or form is not a DOT refusal at all. Refusals in full are in why a refusal counts as a positive.

A short checklist for the carrier

1. Write both thresholds into your policy. State the 24-hour minimum and the next-duty-period rule verbatim, and say whether the company adds anything under its own independent authority.
2. Give the DER a direct phone line and tell your provider about it. 40.255(a)(5)(i) requires the BAT to notify the DER directly for any result of 0.02 or greater, not through a C/TPA. A result sitting in a portal nobody watches is a removal that did not happen on time.
3. Never let the person who called reasonable suspicion run the test. 382.307(c) has no exception, and it is one of the first things an investigator checks in a small fleet where one person does everything.
4. Ask your collection site which device confirms. If the site has only an ASD, it can screen but cannot finish the job, and you will be transporting an observed employee to a second location on a 30-minute clock. Verifying your consortium is the same exercise: see how to choose and verify a consortium or TPA.
5. Report inside three business days, and only what is reportable. A 0.04 or greater goes in. A 0.03 does not, and 382.705(e) prohibits reporting what you know or should know is inaccurate.

FAQ

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• Эта статья на русском