Driving after consuming alcohol is one of the most heavily regulated criminal offences in Canada. Ontario imposes strict rules to protect public safety, and one of the most essential concepts for drivers to understand is the “Over 80” rule. This threshold — 80 milligrams of alcohol in 100 millilitres of blood (0.08) — determines when a driver may be criminally charged with impaired driving under the Criminal Code.
However, impaired driving laws have changed significantly over the past decade. Mandatory alcohol screening, updated penalties, and new enforcement standards mean many older explanations of the law are now outdated. This updated guide provides a modern, accurate, and practical breakdown of what “Over 80” means today, how police assess impairment, and what drivers should expect if charged.
The Criminal Code makes it illegal to operate a motor vehicle with a BAC of 0.08 or higher. This is commonly called “Over 80.” But the law goes further. Police may also charge a person with impaired driving below 0.08 if their ability to operate a vehicle is affected — for example, if their driving is erratic, slow, or unsafe.
Ontario’s provincial rules are even stricter. Drivers can face immediate roadside penalties beginning at 0.05 BAC, even if no criminal charges are laid.
Being under 0.08 is not a guarantee of safety.
This is why understanding what leads to a high BAC — and how it is measured — is crucial.
Alcohol affects every individual differently, and there is no universal number of drinks that is guaranteed safe. Metabolism, food intake, fatigue, medication, hydration, and body composition all influence BAC. The only reliable way to know your BAC is through a breath test.
Still, standard drink guidelines provide a rough estimate of how quickly a person might reach or exceed 0.08.
| Type of Alcohol | Standard Serving | ABV | Counts as 1 Drink |
|---|---|---|---|
| Beer | 12 oz / 341 mL | 5% | ✔ |
| Wine | 5 oz / 142 mL | 12% | ✔ |
| Spirits | 1.5 oz / 43 mL | 40% | ✔ |
| Body Weight | Women (drinks to reach 0.08) | Men (drinks to reach 0.08) |
|---|---|---|
| 50–57 kg | 2 drinks | 2–3 drinks |
| 57–80 kg | 2–3 drinks | 3–4 drinks |
| 80–90+ kg | 3–4 drinks | 4–5 drinks |
Even with these estimates, many people underestimate their level of impairment.
As Jeff Mass, Managing Partner at Mass Tsang LLP , often warns clients:
“Feeling sober is not the same as being under the legal limit. BAC rises silently and unpredictably — and police rely on numbers, not feelings.”
Alcohol impacts the brain unevenly, and judgment is one of the first functions to weaken. Even after one drink, people often underestimate their level of impairment and overestimate their ability to drive safely.
This mismatch between confidence and actual impairment can easily lead to an over 80 charge, even for drivers who believe they are “good to go.” Experienced drinkers are particularly vulnerable because tolerance affects perceived impairment, not BAC levels.
Impaired driving offences apply to more than just cars. Under the Criminal Code and the Highway Traffic Act, “motor vehicle” includes:
If the vehicle is motorized and driven in a public-accessible area, impaired driving laws likely apply.
Modern impaired driving enforcement is very different from what it was 10 years ago. Since 2018, police officers can demand a roadside breath test without needing suspicion that a driver has consumed alcohol. This is called mandatory alcohol screening, and it is lawful as long as the vehicle stop itself was lawful.
Refusing the test results in a criminal offence equivalent to an impaired driving conviction — with the same penalties or worse.
As Robbie Tsang, Managing Partner and Criminal Defence Lawyer , notes:
“A refusal charge is treated just as seriously as an Over 80 charge — sometimes even more so. Comply with the test first; challenge the legality later with your lawyer.”
If a roadside test registers a “Fail” (typically ≥100 mg%), the driver will be arrested and taken to the police station for official testing on an approved instrument such as the Intoxilyzer.
The official process includes:
If officers do not follow the proper procedures — for example, failing to conduct the observation period or improperly handling the machine — the results may be challenged in court.
Regardless of whether criminal charges follow, Ontario imposes immediate penalties for a BAC of 0.05 or higher.
| BAC Level / Behaviour | Immediate Penalty |
|---|---|
| 0.05–0.079 (first time) | 3-day licence suspension |
| 0.05–0.079 (second) | 7-day suspension + mandatory program |
| 0.05–0.079 (third) | 30-day suspension + increased sanctions |
| Fail (≥0.100) | 90-day licence suspension + 7-day vehicle impound |
These penalties occur even before court proceedings begin.
| Penalty | Amount |
|---|---|
| Fine | Minimum $1,000 |
| Ignition interlock | 1 year |
| Criminal record | Yes |
| Driving ban | Minimum 1 year |
| Penalty | Amount |
|---|---|
| Jail | Minimum 30 days |
| Interlock | 3 years |
| Driving ban | Minimum 2–3 years |
| Penalty | Amount |
|---|---|
| Jail | Minimum 120 days |
| Interlock | Potential lifetime requirement |
| Driving ban | Up to a lifetime prohibition |
Many people focus only on fines and suspensions, but long-term consequences often cause the most disruption:
An impaired driving conviction is not just a traffic matter — it becomes a permanent part of your criminal history.
Every DUI case is unique. Small details — such as timing, officer notes, testing errors, or Charter violations — can dramatically change the outcome of a case. A lawyer experienced in impaired driving law will know where procedural failures typically occur and how to challenge them.
Legal defence strategies may include:
A strong legal strategy can lead to:
Your early actions can significantly influence your defence strategy.
A dedicated DUI lawyer manages all stages of your defence, including:
Our team has defended hundreds of impaired driving cases, often achieving dismissals, reductions, or alternative resolutions that protect clients from lifelong consequences.
Brian Brody, Criminal Defence Lawyer Partner , explains the firm’s philosophy clearly:
“Our role is not just to defend a charge — it’s to protect a person’s future. For many clients, a DUI is the most stressful moment of their lives. We guide them through every step with clarity and strategy.”
An Over 80 charge can feel overwhelming, but the situation is far from hopeless. The law is complex, and the outcome depends heavily on the decisions you make in the early stages. With experienced legal representation, many clients avoid criminal records, reduce penalties, or have their charges dismissed entirely.
If you have been charged with over 80, impaired driving, or refusing to provide a breath sample, the experienced Toronto DUI Lawyer team at Mass Tsang LLP is ready to help protect your rights and guide you through the legal process.
We understand how overwhelming a DUI charge can be — from the risk of losing your licence to potential criminal penalties. Our lawyers will thoroughly review the circumstances of your stop, the legality of the demand, the accuracy of the testing procedure, and any possible Charter violations that could strengthen your defence.
Contact us now to schedule a free, confidential consultation.
The sooner you speak with a lawyer, the more options you may have.
The Over 80 rule refers to the legal limit for blood alcohol concentration in Canada. If you operate a vehicle with a BAC of 0.08 (80 mg of alcohol in 100 mL of blood) or higher, you may be charged with a criminal impaired driving offence.
Yes. Police can charge you with impaired driving even below 0.08 if your ability to operate a vehicle is affected. Ontario also imposes immediate roadside penalties starting at 0.05 BAC.
Yes. Under mandatory alcohol screening laws, Ontario police may demand a roadside breath test without needing suspicion that you consumed alcohol.
Refusing a breath test is a criminal offence treated the same as impaired driving. You may face a licence suspension, fines, a criminal record, and other penalties.
Breathalyzer devices are legally recognized as accurate, but testing errors, calibration issues, timing problems, or Charter violations can make the results challengeable in court.
A first Over 80 conviction carries a minimum $1,000 fine, a criminal record, a one-year driving prohibition, and mandatory ignition interlock participation.
Jail is not mandatory for a first offence but is required for repeat offences: at least 30 days for a second offence and a minimum of 120 days for a third or subsequent conviction.
Long-term consequences may include employment issues, loss of professional licences, higher insurance premiums, difficulties entering the U.S., and immigration complications.
Yes. Charges may be withdrawn due to Charter violations, improper breath testing procedures, insufficient grounds for arrest, or other legal errors. Many cases are resolved without a conviction when properly defended.
Yes. DUI law is complex and highly technical. A lawyer can challenge evidence, negotiate with the Crown, identify legal defences, and protect your rights and long-term future.
