First of all , you should know what is impaired driving.

According to the policing section of canada.ca , this offence is one of the main criminal cause of death and also injury in Canada.

This offence occurs when a person drives a vehicle while he/she is drunk or used drugs.

In fact , driving while impaired to any degree by drugs, alcohol, is crime.

The Penalties for this offence depends on seriousness of it. it’s range from a mandatory minimum fine to life imprisonment.

Sometimes, a drunk driving offence is accompanied with another charge.

َActually there are separate offences of having specified prohibited levels of alcohol.

also in cannabis or certain other drugs in the blood within two hours of driving.

Alcohol. prohibited BAC ( The prohibited blood-alcohol concentration) is 80 mg of alcohol per 100 ml of blood.
Cannabis/Weed/marijuana (THC). It has 2 prohibited levels. 1-Primary psychoactive component of weed. ( between 2 ng and 5 ng THC per mililitres if blood). 2- level two is a more serious offence ( 5 ng of THC or more per mililitres of blood )
Combination of Weed and Alcohol.

Having any detectable amount of other drugs in your body within 2 hours of driving is also prohibited. Drugs like :

Impaired driving is a serious offence that poses a massive threat to public safety.

fines for committing this conduct can be different. it depends on the alcohol or drug concentration. whether it is your first or a repeated offence.

also if you have caused bodily harm or death to another person or not.

Impaired Driving Laws in Canada