Police drunk driving stop

How to maintain a safe blood alcohol level

Australia takes drunk driving prevention seriously. Around a fifth of all the road deaths in the country every year are caused by drunken drivers, and countless more people are injured or suffer damage to property in drunk driving incidents.

As a result, Australia enforces a strict limit on driver blood alcohol concentration (BAC), with penalties applying to any driver caught with a BAC over 0.05. Those drivers who insist on driving with a BAC over 0.05 BAC not only risk serious legal consequences, but are hundreds of times more likely to become involved in a serious accident.

Here’s how you can maintain a safe blood alcohol level in Australia.

P platers or learner? Don’t drink at all

The margin for error for P platers and learners is exactly zero when it comes to drunk driving. Every state and territory requires novice drivers to maintain a 0 BAC when behind the wheel.

This not only means that drinking any number of drinks before driving is prohibited, but that young drivers should also refrain from driving the morning after a heavy night of drinking.

If you’re a young driver and have had a heavy night, wait at least 24 hours before getting behind the wheel of a car, or you might get caught with a BAC over 0 and find yourself facing a suspension or having to restart your license.

Know your limits

Staying under the required BAC of 0.05 can be tricky due to the fact that the number of drinks it takes to reach this limit can vary considerably from one person to the next.

As a rule of thumb a woman weighing between 63 and 81 kilograms will reach her legal BAC limit somewhere during the course of her second drink*. Meanwhile a male weighing between 81 and 100 kilograms can have two drinks before hitting the 0.05 BAC limit. By the end of the third drink men and women of all weights will have reached a BAC of 0.05.

The following table provides a fuller picture of estimated BAC across a range of weights for both genders.

SexDrinks*45 KG63 KG81 KG100 KG
Male10,040,030,020,02
Female10,050,040,030,02
Male20,090,060,050,04
Female20,10,070,060,05
Male30,130,090,070,06
Female30,150,110,080,07
Male50,220,160,120,1
Female50,250,180,140,12
Male100,440,310,240,2
Female100,510,360,280,23

*A drink is considered to be 340ml beer/125ml wine/25ml spirits.

Note that you should not rely on how drunk you feel to determine whether or not you are over the legal limit. One of the first things to go out the window when you hit a BAC of 0.05 is your judgement and inhibitions, which means you cannot rely on your judgement once you have had more than one drink.

As you drink more you are also likely to feel more confident and take more risks, while your risk of involvement in serious car accidents simultaneously skyrockets.

Eat something

If you’re drinking and may have to get behind the wheel of a car, have something to eat and then keep snacking while you drink. Having a full stomach slows down the absorption of alcohol into your bloodstream.

Stick to one drink an hour

Your body will metabolize some of the alcohol you are drinking while you are in a drinking session. You can use this to control how quickly your blood alcohol level rises.

A standard drink can take between one and two hours to metabolize, so sticking to one drink an hour will reduce the risk of going over the legal BAC substantially if you are only having a couple of drinks. A good way to enforce this is to have a non-alcoholic drink between alcoholic beverages.

Wait an hour after your last drink before driving

If you have had two to three drinks and suspect you may be over the legal BAC, wait an hour before you get into your car. If you still feel tipsy at this point, get someone else to take you home.

Purchase a home breathalyser

It’s best not to rely on your own assessment of how drunk you are if you will be driving. A variety of breathalyser test kits are available which meet the required Australian standards and can be recalibrated by trained professionals when required.

Having one of these in your vehicle and using it before you drive will provide you with the most reliable indication of whether or not you should be driving.

Ignore the BAC reduction myths

If you’re drunk you’re going to get plenty of bad advice from equally inebriated people on how you can rapidly decrease your blood alcohol concentration.

The following popular BAC reduction methods have been proven to be totally ineffective:

  • splashing your face with cold water or taking a shower
  • drinking coffee or energy drinks
  • drinking lots of water before driving.

Did you know?

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