Breathalyzer Tests in Massachusetts: Know Your Rights

Consequences of Refusing a Breathalyzer Test

Massachusetts’s implied consent law means that by driving on state roads, you’ve agreed to submit to a chemical breath test if arrested for OUI. Refusing comes with automatic administrative penalties from the RMV—separate from any criminal case outcome:

What Happens If You Fail the Breathalyzer?

A breathalyzer result of .08 BAC or higher creates a presumption of impairment under Massachusetts law, triggering a 30-day automatic license suspension. For drivers under 21, the threshold is much lower—a reading of just .02 BAC can result in suspension under the state’s zero-tolerance policy.

However, a failed test is far from a guaranteed conviction. Legal precedents and procedural requirements provide multiple avenues to challenge the validity of these results in court.

The 15-Minute Observation Requirement

Massachusetts law mandates strict procedures before any breath test can be administered. Under 501 CMR § 2.55, the breath test operator must continuously observe the subject for a minimum of 15 minutes immediately before the test.

During this observation period, the subject must refrain from:

• Eating or drinking anything
• Smoking or vaping
• Burping, belching, or hiccupping
• Vomiting or regurgitating

Any of these activities can introduce mouth alcohol or contaminants that artificially inflate the reading. If the operator fails to maintain proper observation—or if any of these events occur and the test proceeds anyway—an experienced defense attorney can move to suppress the results entirely.

Your Right to Refuse: Protections Under Massachusetts Law

Massachusetts law offers meaningful protections if you choose to refuse a breathalyzer test:

• The district attorney cannot comment on your refusal in court
• Your refusal cannot be used as evidence against you at trial
• The jury will never hear that you declined the test

These protections help prevent biased interpretations and preserve your right to avoid potentially unreliable testing. While refusal carries administrative license consequences, it eliminates what is often the prosecution’s strongest piece of evidence.

Can Breathalyzer Results Be Excluded From Evidence?

Breathalyzer results do not automatically hold up in court. The prosecution bears the burden of proving that:

• The test followed all legal standards and protocols
• The machine was functioning properly at the time of testing
• The device received calibration and maintenance every six months
• Calibration tests used a .15 percent alcohol solution to verify accuracy
• The operator was properly certified
• The 15-minute observation period was properly conducted

If any of these standards aren’t met, or if doubts arise about the machine’s reliability, an experienced attorney can challenge the results and work to have them excluded from evidence.

Factors That Can Cause False Positive Results

Breathalyzer machines are not infallible. Multiple environmental and physiological factors can produce inflated or entirely inaccurate results:

Mouth Contaminants

Vomit, blood, or residual alcohol from mouthwash or toothpaste can affect readings. Even food particles trapped between teeth can interact with the test and produce misleading results.

Radio Frequency Interference

Radio waves from nearby cellphones, police radios, or other electronic devices can interfere with the breathalyzer machine. Since law enforcement officers routinely use radios near these devices, this is a well-documented risk factor.

Cigarette Smoke

Cigarette smoke can elevate breathalyzer results, putting smokers at a disadvantage if they smoked shortly before testing.

Medical Conditions

Conditions such as GERD (acid reflux), diabetes, and certain diets (e.g., ketogenic) can produce acetone or other compounds that breathalyzer machines may incorrectly register as alcohol.

The Draeger Alcotest 9510 — Massachusetts’s Approved Instrument

Every evidentiary breath test in a Massachusetts OUI case is performed on the Draeger Alcotest 9510, the only device approved by the State Police Office of Alcohol Testing (OAT) for use in the Commonwealth. The 9510 combines two measurement methods—an electrochemical fuel cell and infrared spectrometry—and requires both readings to agree within a narrow tolerance for a result to be reported.

To be admissible, a 9510 result must come from a unit that meets every one of the following requirements under 501 CMR § 2.00:

• Periodic Annual Certification by an OAT technician within the prior six months, using a 0.15% wet-bath simulator solution
• Pre- and post-test internal accuracy checks within +/- 0.01 of the simulator value
• Two valid breath samples agreeing within 0.02 BAC
• Operator certification current at the time of the test
• 15-minute observation period documented and uninterrupted (see 501 CMR § 2.55)

Any one of these requirements—missed certification window, out-of-tolerance accuracy check, expired operator credential, missing simulator-solution records—is enough to support a motion to suppress. In each OUI case, Attorney Aprodu requests the full OAT certification packet and the periodic maintenance logs for the specific device used and audits them against the regulation before any plea discussion.

The Ananias Decision and What It Means for Your Case

Commonwealth v. Ananias, decided in 2017 by the Massachusetts District Court (Concord) and adopted broadly across the Commonwealth, was the largest breath-test challenge in Massachusetts history. Defense attorneys consolidated thousands of OUI cases and proved that the State Police Office of Alcohol Testing had failed to follow its own certification protocols, that calibration records were incomplete or inconsistent, and that the OAT had withheld worksheets and methodology documents that were discoverable under Brady and Rule 14.

The court excluded breath-test results from a multi-year window of affected cases. More importantly, the decision permanently changed how breath-test evidence is litigated in Massachusetts:

• Mandatory production of the full OAT certification file for the device used, on defense request
• Standing for source-code review of the Alcotest 9510 firmware in appropriate cases
• Express scrutiny of any deviation between the regulation (501 CMR § 2.00) and the OAT’s actual practice
• Specific look at simulator solution lot numbers and traceability of reference standards

Even today, every OUI case in which a breath-test result is offered is litigated against the framework that Ananias established. If the prosecution cannot produce the complete OAT packet, certify the operator, and document the 15-minute observation, the result is vulnerable.

Source-Code and Discovery in Breath-Test Cases

The Draeger Alcotest 9510 is a software-driven instrument. The same firmware decides when a sample is valid, when to abort a measurement, and what reading to report. In a contested OUI case, the defense has a recognized basis to demand discovery of:

• The device certification packet (calibration, maintenance, repair history)
• The OAT technician’s worksheets for the certification performed before and after your test
• Periodic maintenance entries for the specific instrument by serial number
• The operator’s training and certification records
• In appropriate cases, the firmware version, source-code excerpts, and known-defect lists for the unit’s software

Source-code review is not automatic—it is a litigated discovery request that has succeeded in Massachusetts OUI cases since Ananias. When granted, it has uncovered measurement and reporting issues that the prosecution’s expert witnesses could not explain on the stand. Even when source-code review is not pursued, the certification-packet review alone often produces grounds to suppress.