Failing an interlock test when you haven't been drinking

An interlock measures alcohol in your breath, and it can't tell a drink from alcohol still sitting in your mouth from mouthwash, some foods or a spray. Waiting before you blow and rinsing with water are what the companies themselves tell drivers to do.

Updated Oct 23, 2026How we check

Can mouthwash, food or sanitizer set off an interlock?

Intoxalock's own FAQ says its devices detect any source of alcohol and names mouthwash, perfume, hand sanitizer, household cleaners and some automotive products such as wiper fluid.¹

How to avoid a false positive

Wait 15 minutes after eating or drinking anything before you blow.²
Rinse with water or an alcohol-free mouthwash before a test.³
Switch products that contain alcohol, like mouthwash and breath spray, for alcohol-free versions while the device is installed.
Keep sanitizer and sprays out of the car, or use them well before a test with the windows open.

If you fail and you know you're sober

Retest when the device lets you, after rinsing with water. On a failed start-up test you may be asked to retest several times; during a rolling retest, the device keeps asking until you pass or turn off the car.⁴ Then write down the time, what you'd eaten or used, and the retest result, and call the company the same day to ask for the event record. Ask how your state handles a contested reading; the violations guide links to each state's rules.

The alcohol limit the device uses

States set the breath-alcohol level at which the device blocks a start, and it's set well below the legal limit for driving.

State	Device limit
Connecticut	The device keeps the vehicle from starting until your blood alcohol content reads below 0.025.⁵
District of Columbia	The breath alcohol limit for the program is 0.020.⁶
Florida	The device prevents the car from starting when blood alcohol is above 0.025 percent, unless the court specifies a different level.⁷
Idaho	The calibration setting at which the interlock prevents the vehicle from starting is 0.025.⁸
Illinois	Certified devices are built with an alcohol set point of 0.025.⁹
Kentucky	The device keeps the vehicle from starting if your breath alcohol is over 0.02.¹⁰
Minnesota	The device prevents the vehicle from starting when your breath alcohol is 0.02 or higher.¹¹
New Jersey	The device uses a set point of 0.05%, and service visits can be no more than 60 days apart. Installation has to happen at an MVC-designated service center.¹²
North Carolina	While the requirement is in effect, you may not drive with an alcohol concentration of 0.02 or greater.¹³
South Carolina	The vehicle will not start when your breath alcohol is 0.020% or higher, and a reading at that level after the vehicle has started is recorded as a violation.¹⁴
Vermont	The device is set at 0.02 BAC.¹⁵
West Virginia	The vehicle will not start at a BAC of 0.025 or higher.¹⁶
Wisconsin	The device uses a 0.02 setpoint, and while you are subject to an IID order you may not drive with a blood alcohol concentration above 0.02.¹⁷

What a lockout costs

Repeated fails can lock the device until a service visit or an unlock code. These are the fees companies publish or file with New York State.

Company	Lockout and reset fees
Smart Start	$80.00 · Service lockout fee · Filed in New York¹⁸ $80.00 · Violation lockout fee · Filed in New York¹⁹ $63.00 · Unlock code · Filed in New York²⁰
Intoxalock	$75.00 · Lockout reset fee · Filed in New York²¹ $40.00 · Reset/recal fee · Filed in New York²²
LifeSafer	$56.25 · Lockout override or violation fee · Class 1, filed in New York, Feb 2025 v2 schedule²³
RoadGuard	$75.00 · Violation reset · Filed in New York²⁴ $25.00 · Unlock device code (lockout) · Filed in New York²⁵
Low Cost Interlock	$125 · Unlock code after a lockout · National, varies by state and vehicle²⁶ $125 · Typical lockout or reset fee (from the FAQ) · National²⁷

More on what happens after a violation: interlock violations by state.

More guides

Sources 27 sources from 16 sites, including intoxalock.com, cga.ct.gov, dmv.dc.govShow

Every fact on this page comes from one of these.

Ignition interlock devices are designed to detect any source of alcohol, including substances like mouthwash, perfume, hand sanitizer, household cleaners, and even some automotive products like wiper fluid.intoxalock.com/ignition-interlock-devices/faq
Wait at least 15 minutes after eating or drinking before submitting a breath sample.intoxalock.com/ignition-interlock-devices/faq
If you need to rinse your mouth, use water or an alcohol-free mouthwash.intoxalock.com/ignition-interlock-devices/faq
Failed Random Retest While Driving: You'll be prompted to retest until you pass or turn off the ignition.intoxalock.com/ignition-interlock-devices/faq
until the blood alcohol content of such operator is less than twenty-five thousandths of one per centcga.ct.gov/current/pub/chap_248.htm
The BrAC for the program is 0.020.dmv.dc.gov/page/iid-program-frequently-asked-questions
in excess of 0.025 percentleg.state.fl.us/statutes/index.cfm
The calibration setting at which the ignition interlock system will preventlegislature.idaho.gov/statutesrules/idstat/title18/t18ch80/sect18-8008
Any BAIID to be certified shall be designed and constructed with an alcohol setpoint of 0.025ilga.gov/commission/jcar/admincode/092/092010010D04420R.html
over 0.02drive.ky.gov/driver-licensing/Pages/Ignition-Interlock-Program.aspx
0.02 or higherrevisor.mn.gov/statutes/cite/171.306
The breath alcohol concentration (BAC) set point must be at 0.05%.nj.gov/mvc/business/breathalcohol.htm
A requirement that the person not drive with an alcohol concentration of 0.02 or greater.ncleg.gov/EnactedLegislation/Statutes/HTML/BySection/Chapter_20/GS_20-17.8.html
if the driver’s BrAC is at or above .020%, the vehicle will not startppp.sc.gov/sites/dppps/files/Documents/Ignition Interlock/IID_Brochure_May_2024.
That level shall be 0.02 Blood Alcohol Content (BAC).dmv.vermont.gov/node/238
results in a Blood Alcohol Content (BAC) of 0.025 or higherwebapps.transportation.wv.gov/TWS/WVDOTDocumentStorageMigration/PDF/Transportation/DMV/DMVFormSearc
may not operate a motor vehicle with a blood alcohol concentration above 0.02wisconsindot.gov/Pages/dmv/license-drvs/susp-or-rvkd/IID.aspx
Service Lockout Feecriminaljustice.ny.gov/opca/pdfs/Smart Start- NY State Pricing Schedule 04242025.pdf
Violation Lockout Feecriminaljustice.ny.gov/opca/pdfs/Smart Start- NY State Pricing Schedule 04242025.pdf
Unlock Codecriminaljustice.ny.gov/opca/pdfs/Smart Start- NY State Pricing Schedule 04242025.pdf
Lockout Reset Feecriminaljustice.ny.gov/opca/pdfs/Intoxalock-Device-and-Fee-Schedule-8-15-2021.pdf
Reset Recal Feecriminaljustice.ny.gov/opca/pdfs/Intoxalock-Device-and-Fee-Schedule-8-15-2021.pdf
Lockout Override/Violation Feecriminaljustice.ny.gov/opca/pdfs/LifeSafer NY_Pricing 123 February 2025 v2.pdf
Violation Resetcriminaljustice.ny.gov/opca/pdfs/Draeger-Device-and-Fee-Schedule-8-15-2021.pdf
Unlock device code (Lockout)criminaljustice.ny.gov/opca/pdfs/Draeger-Device-and-Fee-Schedule-8-15-2021.pdf
Unlock codelowcostinterlock.com/ignition-interlock-pricing
Typical Lockout or Reset Fees are $125lowcostinterlock.com/faqs