Updated 20 March 2014

One drink could land you in jail

If you are female and small (weigh 45kg), a single glass of wine could have you on or slightly over the legal limit for driving, 0,05g/100ml.


If you are female and small (weigh 45kg), a single glass of wine could have you on or slightly over the legal limit for driving, 0,05g/100ml.

Speed and alcohol are the big killers on our roads, insists the Arrive Alive campaign. "The combination of these two factors takes its toll particularly over weekends, when the lethal speed/alcohol cocktail accounts for more than 60% of the weekly total of crashes."

This was obviously taken into account when the legal alcohol limit was reduced from 0,08g/100ml to 0,05g/100ml several years ago. There's a lobby to have it reduced even further.

So how much can you drink and still drive?
A unit of alcohol is one beer (330ml), one standard size glass of wine, or one standard tot measure of spirits.

Other factors to consider are whether your stomach is empty and how much time has elapsed between having the drink and getting in behind the steering wheel.

Calculate your alcohol levels
Here's a great new tool to calculate your blood alcohol levels. You can also take a look at the table below, provided by the Medical Research Council (MRC), which outlines approximate blood alcohol levels according to number of units/drinks, gender and body weight.

This is a generalised chart based on a person who is metabolising one drink an hour. These figures represent blood alcohol levels for up to one hour after alcohol intake. Blood alcohol levels are measured in grams per 100ml of blood.

Drinks 45 kg 63 kg 81 kg 100 kg Gender
1 0,04 0,03 0,02 0,02 Male
  0,05 0,04 0,03 0,02 Female
2 0,09 0,06 0,05 0,04 Male
  0,1 0,07 0,06 0,05 Female
3 0,13 0,09 0,07 0,06 Male
  0,15 0,11 0,08 0,07 Female
5 0,22 0,16 0,12 0,1 Male
  0,25 0,18 0,14 0,12 Female
10 0,44 0,31 0,24 0,2 Male
  0,51 0,36 0,28 0,23 Female

Tips on reducing the effects of alcohol
You can reduce the effects of alcohol in your body by not drinking on an empty stomach, by eating fatty foods, such as chips and peanuts while you are drinking, and drinking plenty of water in between drinks.

(Susan Erasmus, Health24, updated July 2012)

Read more:
The six stages of drunkenness
Blood alcohol calculations


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