If you are stopped by a police officer in Ontario, they can usually demand that you give a breath sample on an Approved Screening Device (ASD). But can you challenge this request, and can you challenge the results?
That’s what we’re going to look at here. Challenging an ASD often involves technical parts of the law, but it can be done in some circumstances. By the end, you’ll have clarity on if and how to challenge an ASD demand.
What is an ASD Demand?
An ASD is the term used for a handheld road breathalyzer test. It used to be the case that the police could only ask for this if they reasonably suspected that you had consumed alcohol, such as smelling it on your breath or witnessing impaired driving.
However, since 2018, they can now demand a breath sample anytime they conduct a lawful stop with Mandatory Alcohol Screening (MAS). Refusal to take the test is a criminal offence, and you need to comply immediately.
Related Article: https://www.agpllp.ca/the-legal-implications-of-refusing-a-breathalyzer-test-in-canada/
How to Challenge an ASD Demand at the Roadside
If you are asked to provide a breath sample at the roadside, make sure you comply unless you are physically incapable of doing so. This has to be literally incapable, as any half-excuse won’t be accepted by the court.
Simply put, you should not challenge an ASD at the roadside. This applies even if you think the stop was unlawful, your rights were violated, or any other aspect of the test is in contradiction of the law and the correct process.
If you refuse a test, you will be treated as if you failed the test. This means all the same criminal punishments except for the fine, which will be even higher. The other consequences, such as a driving ban and sky-high insurance rates, will also apply.
It’s due to these repercussions that breathing into the ASD is the wisest thing to do. If you think it should be challenged, this should be in court rather than on the roadside. Leave it in the hands of an experienced DUI lawyer rather than trying to remember the law after being pulled over.
Related Article: https://www.agpllp.ca/10-common-dui-defence-strategies-in-ontario/
Challenging the Stop and Demand
Once you contact a lawyer, it’s important to detail to them the exact timeline of events and how the officers conducted the test. The officers must have had a reason for the stop and have had an ASD device with them. The demand for the test also needs to be immediate.
Since the introduction of the MAS, the police have broad legal authority to demand an ASD test. Even if you were lawfully pulled over for another reason, such as a document check, they can ask for a breath test even without any suspicion.
There are other aspects of the stop which could be challenged as we detailed above. For example, you cannot be held while another police car brings an ASD. If you were held for no reason other than to wait, this could invalidate the demand.
It’s important to note that you have no right to legal counsel before taking a roadside breathalyzer test. Once you have been arrested and taken to the station, your right to counsel kicks in. You have the right to speak to a lawyer before any additional test, but not at the roadside.

Challenging the Validity of the Test
It’s important to check if there were any problems with the device or how it was used. The test must be carried out by a qualified technician, it needs to be done by a certified and maintained machine, and two breath samples need to be taken at least 15 minutes apart.
The defence can challenge the functionality of the ASD in many ways. This includes checking maintenance logs, calibration records, technician records, and maintenance test results. Any issues at this point could deem the results inadmissible.
Proving Your Physical Inability to Use an ASD
If you refused to take the test on medical grounds, then you’ll need to prove that you genuinely couldn’t provide a sample. This will require medical evidence of a documented condition that would stop you from blowing into the test.
The likes of a chest infection, anxiety, or a cold are not going to be accepted. Just because it may be difficult to take the test, it doesn’t exempt you from it. Speculation or self-reporting won’t be accepted.
Even conditions such as asthma or lung issues are often invalid excuses, as you may have been able to produce a breath sample at that time. As mentioned above, a breath test should only be refused if it would genuinely be impossible for you to safely provide one.
FAQs
How can I challenge an ASD demand?
By getting a lawyer and going through the courts. You need to comply with the roadside and then speak to a legal expert if you feel the ASD demand was incorrectly requested or completed.
Can I refuse to blow into an ASD?
Yes, the police can’t force you to take one. However, this is never a wise thing to do as it is a criminal offence. The only time an ASD demand should be refused is if you were genuinely medically incapable.
Do I have the right to speak to a lawyer before taking a roadside test?
No, and this is a common misconception. If you fail the test and are arrested, you can then speak to a lawyer. This includes before taking any further tests at the station.
Can I challenge the validity of the ASD test or demand it in court?
Absolutely. However, it can be difficult to challenge. Your lawyer will go through all the relevant information and records. If the correct procedures were followed and the ASD was maintained and correctly working, a legal challenge is unlikely to be successful.
Is it possible to change my mind after refusing an ASD test?
Only if you do so very quickly. A part of the lawful nature of the test is that it needs to be completed immediately. It will be up to the discretion of the officer whether your change of mind meets this requirement. Not doing an immediate test may invalidate the results. Therefore, it can make sense for them to stick with the refusal charge.
Final Thoughts
Challenging an ASD demand is always possible. Crucially, this has to be done in the courts and not by the roadside. The law can be complex, and getting a lawyer to carefully review the details of the case after your arrest will always be the wisest move.
There are many procedures and checks the police need to follow, so there is often a way to challenge the demand. If you’re in need of experienced legal advice, AGP LLP is here to help. Contact us today, and we’ll see if there could be a way to challenge your ASD demand.
