Can I refuse a breathalyzer test with Ignition Interlock ?

You can  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.