Challenging Breathalyzer and Blood Test Results

If you’ve been charged with impaired driving in Alberta after failing a breathalyzer or blood test, you still have options. At Davidson Gregory, our DUI and Impaired Driving Defence Lawyers focus on uncovering testing errors, protecting your rights, and challenging unreliable evidence to help reduce or dismiss your charges.

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Alberta Lawyers for Challenging Breathalyzer and Blood Test Results

Having an experienced DUI and impaired driving defence lawyer is essential when challenging breathalyzer or blood test evidence. These tests are not always accurate, and mistakes in calibration, administration, or sample handling can lead to false readings and serious penalties such as licence suspensions, fines, or even jail.

Our team provides strategic legal representation through every stage of the process. From reviewing testing procedures and dealing with the police to challenging unreliable evidence in court. Our goal is minimizing penalties and achieving the best possible outcome for your case.

Reasons for Challenging Breathalyzer and Blood Test Results

Impaired driving charges in Alberta often stem from roadside stops, accidents, or police checks where alcohol or drug use is suspected. Many of these cases result from testing errors, brief lapses in judgment, or medical and environmental factors rather than deliberate misconduct. Fatigue, stress, or prescription medication can all create behaviour that appears impaired, even when your blood alcohol level is within legal limits. Because roadside testing devices can fail due to improper calibration, contaminated samples, or officer error, each case must be carefully reviewed to ensure your rights were respected and that testing procedures were properly followed.

Common Police and Testing Errors

Some of the most common police errors and testing problems we identify in DUI cases include:

Conducting an unlawful or unjustified traffic stop
Failing to provide access to legal counsel before testing
Skipping the mandatory 15-minute observation period before a breath test
Improper test administration or inadequate officer training
Using breathalyzer equipment that was not properly maintained or calibrated

Technical and Medical Factors That Can Affect Breathalyzer and Blood Test Results

Beyond procedural errors, a variety of technical and medical factors can cause false or exaggerated breathalyzer and blood test readings:

Calibration or maintenance issues: Devices that are not serviced regularly can give false readings
Electronic interference: Certain electronics may disrupt breathalyzer sensors
Medical conditions: Acid reflux, asthma, or dental work can skew test results
Rising blood alcohol: A person’s blood alcohol count may be below the legal limit while driving but rise by the time testing occurs

For these reasons, each case requires a careful review of how the stop was conducted, how testing was performed, and whether your rights were respected at every stage of the process.

Speak with an Experienced Criminal Defence Lawyer

Alberta’s Immediate Roadside Sanctions program imposes swift penalties, including license suspensions and vehicle seizures, which begin right away. Individuals have only seven days to request a review through Safe Roads Alberta, making it crucial to act quickly. Prompt legal action allows a defence lawyer to challenge the evidence, preserve critical information, and navigate both the administrative and criminal processes effectively. Taking early steps can make a significant difference in protecting your rights and improving the outcome of your case.

At Davidson Gregory, we guide clients through every stage of the criminal justice process. Our defence team helps clients challenge both administrative and criminal impaired driving charges, ensuring deadlines are met, evidence is preserved, and every legal option is explored. Acting quickly can make a significant difference in protecting your licence and your future.

Frequently Asked Questions About Challenging Breathalyzer and Blood Test Results

What does challenging a breathalyzer or blood test result mean?

It means reviewing how the test was conducted, how the device was maintained, how samples were handled, and whether legal and procedural safeguards were followed, to identify potential errors that can weaken the prosecution’s case.

On what grounds can these tests be challenged?

Common grounds include improper calibration or maintenance of the breathalyzer device, inadequate observation period (mouth alcohol / regurgitation risk), issues with chain of custody for blood samples, failure to follow legal demands properly, or violation of rights under the Canadian Charter of Rights and Freedoms.

If I “failed” a breath test or gave blood over the limit, can I still challenge it?

Yes, “fail” readings are not always conclusive. If there were procedural or technical errors, or rights were breached, the evidence may be excluded or the case weakened. For example, poor device calibration or a delayed blood draw may be relevant.

What is the difference between the administrative sanctions and the criminal charge process in Alberta?

In Alberta, under the Immediate Roadside Sanctions program (IRS) you may receive immediate penalties (licence suspension, impound, etc) for offences such as > 0.08 Blood Alcohol Count or refusal. You generally have only seven days to request a review. Separately, the criminal process (for charges under the Criminal Code of Canada) deals with impaired driving or refusal offences that are more serious. Acting fast is critical.

If a breathalyzer device was used, can its accuracy be challenged?

Yes. Factors such as calibration logs, maintenance records, the observation period before testing (to avoid residual mouth alcohol), the training of the officer, environmental conditions and medical conditions of the driver are all potentially relevant. For example, one article states that “recent use of mouthwash or acid-reflux” can affect readings.

What about a blood test, how can that be challenged?

In Alberta, refusing a demand for a breath or blood sample is itself a criminal offence. The penalties can be as severe as those for impaired driving. Administrative penalties also apply under IRS, including licence suspensions and vehicle impoundments.

What are the consequences of refusing or failing to provide a sample?

Very soon. For IRS sanctions in Alberta, you generally have seven days from the date of the notice to request a review via Safe Roads Alberta. Missing this deadline may forfeit your ability to appeal or challenge the administrative process.

How soon do I need to act if I want to challenge the administrative sanctions?

Yes. Your lawyer can apply to vary conditions to allow communication for parenting purposes or supervised contact when appropriate. Courts consider safety, the nature of the allegation, and the best interests of any children involved.

Does hiring a lawyer matter in these cases?

Yes. Challenging breathalyzer or blood test results involves technical issues (device maintenance, medical factors, procedural compliance), rights issues (Charter) and timing issues (deadlines for administrative appeals). A lawyer experienced in impaired-driving defence can identify errors, preserve evidence, navigate both administrative and criminal processes, and help improve the outcome.