Breath Testing & Intox EC/IR II
No, other states do not all use the same breath machine. Breath test instruments by state fall into a handful of families: North Carolina, Virginia and Arkansas use the Intoximeters Intox EC/IR II, while Florida and Nevada use CMI’s Intoxilyzer 8000, Colorado and Michigan the Intoxilyzer 9000, and California a portable Dräger Alcotest. The brand changes from state to state, but the legal question is the same everywhere: was the state’s own testing rule followed?
Key takeaways
- North Carolina has used the Intox EC/IR II under 10A NCAC 41B .0322 since November 1, 2007.
- Each state picks its own instrument and writes its own rules for observation periods, operator permits and maintenance.
- All of the major evidential models, including the EC/IR II, Intoxilyzer 8000 and 9000, DataMaster DMT and Alcotest 9510, appear on the federal list of approved evidential breath devices.
- A result from one state’s instrument is judged under that state’s rules, not North Carolina’s.
Breath test instruments by state: the short answer
Every state chooses its own evidential breath instrument, usually through its health department, state lab or state police, and then writes rules for how officers must use it. The table below lists only states we could confirm from an official state source as of November 2026. Instruments change with contracts and replacement cycles, so treat any state not listed here as unknown rather than assuming.
| State | Evidential instrument | Manufacturer | Official source |
|---|---|---|---|
| North Carolina | Intox EC/IR II (and EC/IR II Enhanced) | Intoximeters, Inc. | 10A NCAC 41B .0322; NC DHHS |
| Virginia | Intox EC/IR II (on the approved list since 2008) | Intoximeters, Inc. | Virginia Dept. of Forensic Science |
| Arkansas | Intox EC/IR II | Intoximeters, Inc. | Arkansas Dept. of Health operator manual (2023) |
| West Virginia | Intox EC/IR II | Intoximeters, Inc. | West Virginia State Police lab manual |
| Illinois | Several approved: Intox EC/IR and EC/IR II, Alco-Sensor V XL, Intoxilyzer 8000, RBT IV | Intoximeters; CMI | Illinois State Police BAO course |
| Michigan | Intoxilyzer 9000 (validated by MSP in 2023) | CMI, Inc. | Michigan State Police |
| Colorado | Intoxilyzer 9000, statewide | CMI, Inc. | Colorado CDPHE |
| Maine | Transitioning from Intoxilyzer 8000 to Intoxilyzer 9000 | CMI, Inc. | Maine Bureau of Highway Safety |
| Florida | Intoxilyzer 8000 | CMI, Inc. | FDLE Alcohol Testing Program |
| Nevada | Intoxilyzer 8000 | CMI, Inc. | Washoe County Sheriff’s Office forensic lab |
| California (DOJ lab counties) | Alcotest 7510 in the Portable Evidential Breath Testing (PEBT) program | Dräger | California DOJ Bureau of Forensic Services |
The four instrument families you will hear about
Most American evidential testing is done on instruments from four manufacturers: Intoximeters, CMI, National Patent Analytical Systems (DataMaster) and Dräger. The federal Department of Transportation’s list of NHTSA-approved evidential breath devices (last updated January 28, 2025) includes the Intox EC/IR II, the Intoxilyzer 8000 and 9000, the DataMaster DMT and the Alcotest 9510.
Intoximeters, Inc., St. Louis. A fuel cell measures the alcohol while an infrared bench with two ethanol channels and one carbon-dioxide channel monitors the breath, flags mouth alcohol and decides when to draw the deep-lung sample. North Carolina, Virginia, Arkansas and West Virginia use it, and Illinois lists it among several approved instruments. Our full explainer: how the Intox EC/IR II works in North Carolina.
CMI, Inc. The Intoxilyzer 5000 was North Carolina’s instrument before the EC/IR II. Its successors, the 8000 and 9000, are used by Florida and Nevada (8000) and Colorado and Michigan (9000), with Maine moving from the 8000 to the 9000. CMI also makes the Intoxilyzer 500 handheld, which appears on North Carolina’s list of approved roadside screening devices.
National Patent Analytical Systems (NPAS). The federal list shows the DataMaster DMT under both NPAS and Intoximeters. Vermont’s published discovery files include pre-deployment performance testing of the DMT, and a Missouri DWI treatise describes the DMT as new to that state.
Dräger. The Alcotest 9510 is on the federal evidential list. California’s DOJ uses the Alcotest 7510 as a portable evidential instrument in its PEBT program, which the department says supports about 1,200 units, so a California breath test can be taken at the roadside rather than after transport.
The technologies overlap but are not identical. Some instruments quantify alcohol with infrared absorption, some with an electrochemical fuel cell, and some use both. The EC/IR II’s design, fuel cell for the number and infrared for sample quality, is documented by the Virginia Department of Forensic Science. For other models, ask for the operator manual and validation records the state lab relies on rather than relying on marketing descriptions. Michigan, for example, posts its Intoxilyzer 9000 user manual and validation summary online.
The rules differ more than the machines
Two states can use the same instrument and still have different rules. Even among EC/IR II states, the required observation period before a sample is not uniform.
Operator certification varies too. Michigan State Police require breath operators to recertify every two years, while Maine’s operator certificates are valid for three years. North Carolina requires a current DHHS permit for the specific type of instrument, and the courts take judicial notice of the permit list under G.S. 20-139.1(b). Maintenance schedules, accuracy-check tolerances and the number of required samples are all set state by state.
| North Carolina rule (Intox EC/IR II) | Requirement | Source |
|---|---|---|
| Observation period | 15 minutes before each sample | 10A NCAC 41B .0101 |
| Samples | At least two sequential samples, within 0.02; lower result used | G.S. 20-139.1(b3) |
| Accuracy check | 0.08 standard; 0.08 or 0.07 accepted | 10A NCAC 41B .0101 |
| Preventive maintenance | At least every 4 months | 10A NCAC 41B .0323 |
| Operator | Current DHHS permit for the instrument type | G.S. 20-139.1(b) |
North Carolina’s own instrument history
North Carolina has moved through three generations of evidential instruments, from the Breathalyzer to the Intoxilyzer 5000 to today’s Intox EC/IR II. The state program behind them, now the DHHS Forensic Tests for Alcohol Branch, has trained officers in breath testing since 1964.
- 1964North Carolina’s state breath-alcohol program begins training law enforcement in breath testing.
- 1984In State v. Shuping, the N.C. Supreme Court reviews Breathalyzer testing under the then Department of Human Resources rules.
- Through 2008The CMI Intoxilyzer 5000 is in use; DHHS posts its maintenance histories for 2005–2008.
- 2006S.L. 2006-253 requires at least two sequential breath samples.
- Nov. 1, 2007The Intox EC/IR II operating rule, 10A NCAC 41B .0322, takes effect. EC/IR II maintenance records begin in 2008.
- Apr. 1, 2020The EC/IR II “Enhanced” model (serial 10,000 and up) is added; the old Intoxilyzer 5000 rules are later removed from the Code as unnecessary.
Virginia’s forensic lab reports that it put the EC/IR II on its approved list in 2008, so North Carolina and Virginia made the change at about the same time. For North Carolina drivers, the instrument history matters mostly when reading older cases: a 1980s decision about the Breathalyzer or a 2009 decision about the Intoxilyzer 5000 still states good law on the statute, but its facts describe a different machine.
What the courts say, whatever the machine
North Carolina’s appellate decisions follow the instrument of their era, but the principles carry forward: valid results are strong evidence, and the State must follow its own procedures. Two U.S. Supreme Court cases set the constitutional floor for breath testing in every state.
Police may require a breath test without a warrant as a search incident to a lawful drunk-driving arrest, but not a blood test. Breath tests are far less intrusive. This applies in every state regardless of which instrument it uses.
Read the opinion ↗Because a breath test requires deep-lung breath, it implicates bodily-integrity concerns and is a search under the Fourth Amendment. Breath testing therefore must be justified, which is why the stop and arrest always matter.
Read the opinion ↗In the Breathalyzer era, the court held that the 0.01 tolerance on the simulator check is not a margin of error in the subject’s test but a safeguard favoring the defendant, and that a valid reading is sufficient to prove the per se element.
Read the opinion ↗On an Intoxilyzer 5000, two valid readings within 18 minutes, separated by insufficient samples, met the consecutive-test requirement. The same logic was later applied to the EC/IR II.
Read the opinion ↗On an Intox EC/IR II, readings 11 minutes apart after a timeout and reset were sequential and admissible, and the analyst did not have to start a new observation period because the original observation was unbroken.
Read the opinion ↗Out-of-state cases about a particular instrument, such as rulings in other states about software or source code, are not binding in North Carolina and often involve a different machine. When you read about another state’s breath-test controversy, the first question is whether it involved the instrument and the rules North Carolina actually uses.
The brand on the machine changes at the state line. The question does not: did the State follow its own rules?Adkins & Purkey
Myths about breath machines in different states
Tap or hover each card to see the fact behind a common belief.
Tested in another state, or from another state?
If you were arrested in North Carolina, the Intox EC/IR II and North Carolina’s rules apply, wherever your license comes from. If you were tested somewhere else, that state’s instrument and rules apply to that case.
Terminology changes at the state line too: North Carolina calls the offense DWI, while other states use DUI, OWI or OUI. Our article on DWI vs. DUI and other states’ terms explains the differences, and North Carolina charge types covers the related offenses.
Questions to ask about any breath instrument
Whatever the brand, the same handful of records decides whether a breath result holds up. Use this list to organize what you have and what you need.
- Which instrument model and serial number ran the test?
- Is that model approved under the state’s rules on the test date?
- Did the operator hold a current permit or certification for that model?
- Was the observation or deprivation period long enough and unbroken?
- Did the accuracy check pass, and was the gas standard or simulator solution in date?
- Was maintenance current under the state’s schedule?
- Do the sample results agree within the state’s tolerance, and is the right number reported?
- Was the stop lawful and was there probable cause to arrest?
For North Carolina cases, our guides to breath testing records and reviewing DWI evidence show where each record comes from. The UNC School of Government’s overview of North Carolina breath-test rules is a reliable second source.
What this means for your North Carolina case
If you were tested in North Carolina, focus on the Intox EC/IR II record and North Carolina’s rules, not on comparisons with other states. The DMV consequences follow from the North Carolina result as well.
A reading of 0.08 or more, or a refusal, starts a civil license revocation before any court date; see the 30-day civil revocation and all DMV consequences. If the charge came from a roadside reading, read about what a portable breath test can and cannot prove in NC. And if you are deciding what to do next, plea or trial walks through the biggest decision in the case.
From our book
Charged with DWI in North Carolina?
Our book explains the science behind North Carolina’s breath testing in plain language, so you can read your own test record with confidence before you meet with a lawyer.
Breath test instruments by state: FAQ
Does every state use the same breathalyzer?
No. Each state chooses its own evidential instrument. North Carolina, Virginia, Arkansas and West Virginia use the Intox EC/IR II; Florida and Nevada use the Intoxilyzer 8000; Colorado and Michigan use the Intoxilyzer 9000.
What breath machine does North Carolina use?
The Intoximeters Intox EC/IR II, including the Enhanced model with serial number 10,000 or higher, approved under 10A NCAC 41B .0322.
What did North Carolina use before the Intox EC/IR II?
The CMI Intoxilyzer 5000, and before that Breathalyzer instruments. DHHS maintenance records for the Intoxilyzer 5000 cover 2005 through 2008, and the EC/IR II rule took effect November 1, 2007.
Is the Intox EC/IR II federally approved?
Yes. The U.S. Department of Transportation lists the Intox EC/IR II among NHTSA-approved evidential breath devices, along with the Intoxilyzer 8000 and 9000, DataMaster DMT and Alcotest 9510.
If I was tested in another state, do North Carolina’s rules apply?
Generally no. A breath test is judged under the law of the state where it was given. A North Carolina test is judged under North Carolina’s statutes and DHHS rules.
Adkins & Purkey, PLLC
Talk to a North Carolina DWI lawyer
Whether you are a North Carolina resident or visiting from another state, we can review your Intox EC/IR II record and the rules that applied to it. Offices in Huntersville (Lake Norman) and Locust (Stanly County), serving Charlotte, Mecklenburg, Iredell, Cabarrus, Stanly and courts across North Carolina.
General North Carolina legal information as of November 2026, not legal advice for any specific case. Reading this article does not create an attorney-client relationship. Attorney advertising.
