Transportation Minister Kathleen Wynne introduces new regulations for young and novice drivers. Transportation Minister Kathleen Wynne introduces new regulations for young and novice drivers. (CBC)

The Ontario government announced new rules Monday for young and novice drivers that include tougher restrictions on blood-alcohol levels.

Under the rules, which come into effect on Aug. 1, drivers 21 years old and under must have zero blood alcohol levels while behind the wheel, regardless of their licence category.

Under the current system, the zero tolerance policy only applies to those with a G1 or G2 class licence.

Metabolizing alcohol

How your body gets rid of alcohol you have consumed depends on a variety of factors, including age, gender, body size, how much you drank and the health of your liver.

It generally takes an hour to metabolize 15 millilitres of alcohol, about the amount in a standard serving of spirits, wine or beer. But that's only a very rough estimate.

The liver deals with 95 per cent of the alcohol you consume. The rest is eliminated through excretion in breath, urine, sweat, feces, milk and saliva. Your breath and urine are of particular interest to officials looking to determine whether you are impaired.

If you consume four drinks over the course of an hour, it will take about seven hours for your body to get rid of all the alcohol. You can expect to register a blood alcohol content of approximately .05 per cent — regarded as significantly unsafe for driving — four hours after you stop drinking.

If you've had two drinks, your blood alcohol content should peak at just under .05. It will take around 4½ hours for your body to eliminate all the alcohol.

If you're a 59-kilogram (130-pound) woman who's breastfeeding, it will take your body just under five hours to get rid of all the alcohol in two drinks.

Sources: Centre for Addiction and Mental Health, U.S. National Institute on Alcohol Abuse and Alcoholism

"What we're trying to do is introduce sanctions that will educate drivers right up front so they get into good practices early on," Transportation Minister Kathleen Wynne told CBC News.

Anyone caught breaking the new rules will have their licence suspended immediately for 24 hours and could face a further suspension of 30 days, plus a fine of up to $500.

Repeat offenders targeted

The new rules also include a system of escalating sanctions for novice drivers who repeatedly violate traffic rules, Wynne said.

Under the new rules, novice drivers who accumulate four or more demerit points will be given a 30-day suspension for their first conviction, Wynne said.

"On second conviction, it's a 90-day suspension, and then potentially the novice licence could be cancelled and they'll have to start all over again," Wynne said.

"Just telling people things, just saying that you shouldn't drink and drive isn't enough," Wynne said. "We've got to educate people about these dangers, and these sanctions are part of the education."

Wynne said drivers aged 19 to 21 are nearly 1.5 times more likely to be involved in drinking and driving accidents that involve death or injury.

"It will save more lives than any other piece of legislation at a provincial level," said Mothers Against Drunk Driving Canada CEO Andrew Murie.

The zero tolerance for drinking and driving for people 21 and under was passed after the Liberal government backed off another initiative that would have limited teenage drivers to having only one other teen passenger in their vehicles.

There are further sanctions dealing with novice drivers who have too many people in vehicle or are caught for certain speeding offences.

Also effective Aug. 3, eligible drivers convicted of an impaired driving offence for the first time will be able to reduce their licence suspension if they agree to have an ignition interlock device installed in their vehicle, at their expense.

The initiative is aimed at helping impaired drivers change their behaviour to prevent them from becoming repeat offenders, the ministry said in a statement.

With files from The Canadian Press