Select a language

Breathalyzer and roadside tests

Region: Ontario Answer Number: 771

The breathalyzer and roadside tests compared

To test a driver’s alcohol consumption, the police have the legal right to administer two kinds of breath tests, the roadside breath-screening test and the breathalyzer test. The roadside breath-screening test usually takes place at the side of the road after someone has been pulled over. This test, which is sometimes called an A.L.E.R.T. test, provides the police with an approximate reading of the amount of alcohol in the person’s body.

The second test is called the breathalyzer or the intoxilyzer test. Unlike the roadside breath test, the breathalyzer is conducted at the police station. The breathalyzer test is more sophisticated and provides an exact reading of the blood alcohol level. Refusing to provide a breath sample for either test can result in a serious charge under the Canadian Criminal Code. If you have an injury or illness that prevents you from being able to blow enough air into the screening machine, you may have a valid excuse for refusing.

When can the police request a roadside breath test and a breathalyzer?

Before asking a driver to perform a roadside breath test, the police must generally have a good reason to suspect that alcohol has been consumed. This may arise from a number of observations by the police, such as your appearance, your physical movements, whether you or your car smell of alcohol, and your answers to questions.

Although you are not required to respond to questions by the police, failing to do so may lead the police to suspect you have consumed alcohol, and they will likely require you to provide a roadside breath-screening sample. You do not have the right to consult a lawyer before performing the roadside test. However, you do have the legal right to consult a lawyer before performing the breathalyzer test at the police station.


There are penalties under both the Ontario Highway Traffic Act and the Canadian Criminal Code for impaired driving.

Highway Traffic Act

If you fail a roadside sobriety test by registering a blood alcohol concentration of between 0.05 and 0.08 (50 – 80 milligrams of alcohol in every 100 millilitres of blood), the police can immediately suspend your licence for three days for a first occurrence. This is known as the “warn range”. Your licence can be suspended for seven days for a second occurrence and you must undergo an alcohol education or treatment program and an ignition interlock condition will be placed on your licence. Your licence can be suspended for 30 days for a third or subsequent occurrence and you will face a mandatory alcohol education or treatment program and an ignition interlock condition will be placed on your licence.

Any licensed drivers who are 21 and under, regardless of licence class, or novice drivers caught with any alcohol in his or her blood, will receive an immediate 24-hour roadside driver licence suspension and, if convicted, will face a fine of $500 and a minimum 30-day licence suspension.

You are subject to an immediate 90-day roadside licence suspension for refusing a breath test, or for testing over the legal limit of 0.08. You will also have to pay a $180 administrative penalty and your vehicle will be impounded for seven days.

Canadian Criminal Code

You can also be charged under the Criminal Code for refusing to provide a sample and if convicted, would be subject to the same penalties as if you were convicted of driving while impaired.

Although you cannot be charged with an offence for failing a roadside breath test you can be charged under the Criminal Code with several criminal offences for failing a formal breathalyzer test at a police station. Such charges can include: driving while exceeding the legal blood/alcohol limit, impaired driving, dangerous driving, and criminal negligence.

A blood alcohol concentration of more than 0.08 is a criminal offence and will result in an immediate 90-day roadside suspension and your vehicle will be impounded for seven days. If convicted, you will receive a lengthy licence suspension, usually a fine, and mandatory alcohol education or treatment and an ignition interlock condition. Sometimes, the punishment may include jail time (often to be served on weekends). In addition, being convicted of a criminal driving offence means that you will have a criminal record.

Drug-impaired driving

On June 2, 2015 Ontario passed the Making Ontario’s Roads Safer Act in its effort to improve the safety of Ontario roads. As of October 2, 2016, under this Act, drivers who fail a roadside sobriety test and are found to be under the influence of drugs are subject to the same penalties as alcohol impaired drivers. A roadside sobriety test may include walking heel-to toe in a straight line, standing on one foot during a mental challenge, or an eye exam.

Previously, drug impaired drivers faced criminal charges, but did not face licence penalties and suspensions under provincial legislation.

If you were at fault for an automobile accident while you were impaired, your automobile insurance policy might not cover damage to your vehicle and you may not be eligible to receive certain other benefits, such as income replacement benefits.

If the police ask you to perform a formal breathalyzer test, it is your right to consult a lawyer and you should consider doing so.

To erase your criminal record, call toll-free 1-800-874-2652 or learn more at Pardon Pros. It’s easier than you think.

If you have been charged with any criminal offence, contact our preferred criminal law experts, Calvin Barry Criminal Lawyers.


Calvin Banner 1

Pardon Pros Criminal Ontario Sept 2017 – 771Pardon Pros Criminal Ontario Sept 2017 – 771

Was your question answered?


You now have 5 options:

Was your question answered?

Yes    No

What information would you like to see added?

Submit an Edit Request

What are your changes?*

Page loaded. Thank you