When pulled over for suspected drunk driving in Ohio, drivers often encounter a small handheld device that officers ask them to blow into at the roadside. This portable breath test, commonly called a PBT, seems like compelling evidence of intoxication. Yet Ohio law consistently holds that these test results cannot be used in court, creating important protections for drivers that many people do not understand.

The Fundamental Problem with Portable Breath Tests

Portable breath tests occupy a peculiar position in Ohio DUI enforcement. Police officers carry them, use them during traffic stops, and often make arrest decisions after administering them. Despite this widespread use, the results of these tests remain inadmissible in Ohio courts for several critical reasons.

The Ohio Department of Health maintains a list of approved devices for breath alcohol testing under Ohio Administrative Code 3701-53.02. Portable breath tests do not appear on this approved list. Without official recognition and approval, these devices lack the legal foundation necessary for admissibility in criminal proceedings. This administrative exclusion reflects broader concerns about the reliability and accuracy of these roadside devices.

Inherent Unreliability: A Consistent Judicial Finding

Ohio appellate courts across multiple districts have repeatedly characterized portable breath tests as inherently unreliable. This unreliability stems from several factors that distinguish PBTs from the more sophisticated breath testing equipment used at police stations.

Portable breath tests may register inaccurate percentages of alcohol in the breath. More troublingly, they may be inaccurate regarding the presence or absence of any alcohol at all. A device that might show alcohol when none exists, or fail to detect alcohol that is present, cannot meet the standards required for criminal evidence.

The environmental conditions at roadside stops further compromise PBT accuracy. Temperature variations, humidity, and other atmospheric factors can affect readings. Unlike controlled testing environments at police stations, roadside conditions introduce variables that these portable devices cannot adequately account for or correct.

The Crucial Distinction Between BAC and Impairment

The National Highway Traffic Safety Administration's 2023 training manual makes an important acknowledgment about portable breath tests that undercuts their evidentiary value. The manual explicitly states that while PBTs provide direct indication of blood alcohol content levels, they do not indicate the level of the subject's impairment.

This distinction proves crucial in DUI cases. Ohio law prohibits operating a vehicle while impaired by alcohol or with a prohibited blood alcohol concentration. Impairment varies widely among individuals with the same BAC level. Some people show significant impairment at relatively low BAC levels, while others with higher tolerance may display fewer obvious signs of impairment at higher levels. A device that cannot measure actual impairment provides limited value in determining whether someone violated Ohio's DUI laws.

Contamination Concerns and Testing Protocols

The NHTSA manual acknowledges that various contaminants can affect PBT accuracy. Cigarette smoke, residual mouth alcohol from recent drinking, mouthwash, breath mints, and even certain medications can all potentially influence readings. To address these concerns, the manual requires officers to ensure that subjects do not put anything in their mouths for 15 to 20 minutes before testing.

In practice, officers at roadside stops rarely observe this waiting period. The pressure to complete the stop efficiently, combined with safety concerns about prolonged roadside detention, often leads officers to administer PBTs without the recommended observation period. This failure to follow proper protocols makes an already unreliable test even less trustworthy.

The contamination issue extends beyond what subjects put in their mouths. Environmental factors like gasoline fumes, paint vapors, or other airborne chemicals at the roadside can potentially affect readings. These portable devices lack the sophisticated safeguards that stationary breath testing equipment employs to detect and account for interfering substances.

The Legal Status Across Ohio Districts

While most Ohio appellate districts agree on PBT inadmissibility, the reasoning and emphasis vary slightly across jurisdictions. The Third, Fourth, Seventh, Eighth, Tenth, Eleventh, and Twelfth Districts have all issued decisions finding PBT results inadmissible. These courts consistently cite the devices' removal from Ohio Department of Health recognition and their inherent unreliability.

Some courts have gone further, explicitly stating that PBT results cannot serve as probable cause for arrest. This limitation significantly restricts how officers can use these devices. While officers may still administer PBTs as investigative tools, they must establish probable cause through other observations and evidence.

Your Right to Refuse and Its Protection

Given the inadmissibility of PBT results, Ohio courts have extended this protection to include refusal evidence. If the test results themselves cannot be admitted due to unreliability, then evidence that someone refused to take an unreliable test likewise cannot be used against them.

This protection differs significantly from the consequences of refusing chemical tests at the police station. Refusing a breath, blood, or urine test after arrest triggers administrative license suspensions and can be mentioned at trial. Refusing a portable breath test at the roadside, however, carries no such penalties and cannot be presented as evidence of guilt or consciousness of guilt.

Many drivers do not understand this distinction. Officers may imply that refusal will worsen the situation or lead to automatic arrest. While officers can certainly consider refusal along with other observations in deciding whether to arrest, the refusal itself cannot be presented to a judge or jury as evidence of impairment.

Practical Implications for DUI Stops

Understanding the limited role of portable breath tests helps drivers make informed decisions during traffic stops. Officers may still request these tests, and drivers must decide whether to comply. The test results might influence an officer's decision to arrest, even though those results cannot be presented in court.

Other evidence gathered during the stop remains admissible. Officer observations about driving patterns, physical appearance, odor of alcohol, performance on standardized field sobriety tests, and statements made by the driver all can be presented in court. The exclusion of PBT results does not invalidate the entire stop or prevent prosecution based on other evidence.

The Continuing Role of PBTs in Law Enforcement

Despite their inadmissibility, portable breath tests continue to serve law enforcement purposes. Officers use them as preliminary screening tools to help determine whether further investigation is warranted. A reading suggesting the presence of alcohol might prompt more thorough field sobriety testing or support an officer's decision to request chemical testing at the station.

Some officers testify about PBT administration without revealing the numerical results, describing only that they administered the test as part of their investigation. Courts generally permit this limited testimony as it goes to the thoroughness of the investigation rather than the test results themselves.

Protecting Your Rights While Remaining Cooperative

Knowledge about PBT inadmissibility should not be interpreted as license to be uncooperative or hostile during traffic stops. Officers have various tools beyond portable breath tests to establish probable cause for arrest. Aggressive or confrontational behavior can lead to additional charges and complications.

Instead, understanding these limitations allows for informed decision-making. Drivers can politely decline PBT testing while remaining cooperative in other aspects of the stop. If arrested despite refusing the PBT, the focus shifts to the admissible chemical tests at the station, where different rules and consequences apply.

The Importance of Legal Representation

The inadmissibility of portable breath test results represents just one aspect of Ohio DUI law's complexity. Successful defense requires understanding not only what evidence cannot be used, but also how to challenge the evidence that remains. Officer training, field sobriety test administration, chemical test procedures, and constitutional requirements all provide potential avenues for defense.

Those facing DUI charges benefit from early consultation with experienced counsel who can evaluate what evidence the prosecution can actually present. The exclusion of PBT results may seem like a minor victory if other strong evidence exists, but it can prove crucial in cases where the remaining evidence is marginal or questionable.

Moving Forward

Ohio's treatment of portable breath tests reflects a careful balance between law enforcement needs and evidentiary reliability standards. While these devices serve a screening function during investigations, their scientific limitations and lack of official approval properly exclude them from criminal proceedings. Understanding this distinction helps drivers navigate DUI stops more knowledgeably and ensures that convictions rest on reliable, admissible evidence rather than questionable roadside technology.

The law continues to evolve as technology improves and courts address new challenges. For now, however, Ohio drivers can take comfort knowing that those handheld devices at the roadside, despite their official appearance and police reliance on them, cannot be used to prove guilt in court. This protection, grounded in concerns about reliability and accuracy, helps ensure that DUI convictions rest on solid evidentiary foundations rather than unreliable roadside gadgets.