What Is Over the Legal Limit? Some Surprising, Scary Thoughts for Tasting and Drinking

What Is Over the Legal Limit? Some Surprising, Scary Thoughts for Tasting and Drinking


The Cape Wine Lovers’ Society is a strong advocate of safe and responsible drinking. This begs the question – especially for an original UK native like me – as to what is the safe limit for drinking and driving in South Africa. The safest limit of course is not to drink at all but this is not always practical or desirable.

Please read to the end. I guarantee you will both learn and be surprised.

What is the legal limit in South Africa? This is defined in the South African Road Traffic Act 93/96 that has been in effect since March 1998. The legal limit of alcohol concentration for driving a vehicle is:

  • Less than 0.05g per 100ml of blood
  • Less than 0.24mg per 1000ml of breath

Interestingly, and unknown to me, there are even lower limits for professional drivers: 0.02g and 0.10mg per 100ml of blood and 1000ml of breath, respectively.

This is all very well and good but ‘What does this mean for me? How much is over the limit?’ The simple ‘rule of thumb’ is to consume a maximum of 1 unit of alcohol per hour, where 1 standard unit constitutes 1cl (10g) of pure alcohol. This is based on an adult weighing 68kg who has eaten a meal. It equates to the amount of alcohol our bodies can process each hour. It is important to be aware that if you weigh less than 68kg you will need more time to process the same amount of alcohol.

So far so good but for practical purposes I need to know more than this. What does 1 standard unit approximately work out to? The indicated amounts are:

  • 75/90ml of red/white wine depending on the alcohol content, i.e. 75ml if 14% alcohol (red) or 90ml if 12% alcohol (white)
  • One 25ml tot or ‘shooter’ of whisky, brandy, vodka, tequila etc (40% alcohol)
  • 2/3 of a beer or spirit cooler with 5% alcohol content
  • ½ cider
  • 1/4-1/2 cocktail

So far so good, again, but this is where I discovered that the published guidance stops. I had to get my calculator, wine glasses and kitchen measures out to make practical sense. Bear with me through the calculations.

How much is 75/90ml of wine? The average wine glass internationally is about 150ml, which means there are about 5 x 150ml servings from a standard 750ml wine bottle. The glasses in the header photo each contain 75ml red wine or 90ml white wine – 1 unit of alcohol – so you can see the amount. Incidentally, a wine box, such as the Du Toitskloof sauvignon blanc or cabernet sauvignon/shiraz sold by PicknPay, is 3 litres, equivalent to 4 x 750ml bottles or 20 glasses of wine.

This made me think about wine-tasting as distinct, of course, from wine drinking. I wanted to know how these ‘rules of thumb’ equate both for me personally as well as the amount and rate I serve at the Cape Wine Lovers’ Society meetings. How many tastings can I have? Or give? This assumes a spittoon is not used. I measured the amounts of liquid up to the etched tasting line for a Babylonstoren and a Constantia Glen glass. Their standard tasting serving is 35ml, which amounts to 0.4 to 0.5 standard units per serving, depending on whether white or red wine. Many wineries serve 50ml and so the calculations become even more significant.

Eight tastings are therefore 280ml or about 1/3 of a bottle of wine, whereas 6 tastings are 210ml or about ¼ a bottle of wine. Put another way, in terms of the total number of units consumed, the results are scary! They amount to 2.7 and 3.6 standard alcohol units for a 6 and 8 variety tasting, respectively. This means that one should allow close to 3 and 4 hours to taste a selection of 6 and 8 wines if no spittoon is used.

I use a number of techniques to limit my alcohol intake whilst tasting, besides taking a taxi or a reliable non-drinking friend. First, I use a spittoon. This reduces intoxication and maintains my tasting ability. One does not need to swallow to taste. Second, my partner and I generally share tasting. This halves my intake and thus the time needed legally for the driver to complete the tasting.

Additionally, and timely with many wine festivals during the next 1-2 months where you may be faced with several 100 bottles of wine, a good technique is to limit your choice of wine to taste. I try to taste a wine of a particular style or category (e.g. Rosé) or region (e.g. Coastal region) or district (e.g. Stellenbosch) or grape variety (e.g. Chenin Blanc or Pinotage).

Whilst on the topic, let us also consider the couple who drink a bottle of their chosen wine at a restaurant. One 750ml bottle of red wine contains 10 standard units (75ml) of alcohol. Shared equally, that amounts to 5 units each or a minimum of 5 hours safely to consume red wine. This reduces to slightly over 4 hours for white wine for the couple both to be within the legal drink-drive limits.

Remember too that many restaurants serve wine in extra large glasses. One 250ml glass of red wine, for instance, can come to over 3 units – which puts everyone over the legal limit (0.06g).

Here is something else that I didn’t know. ‘Lite’ and ‘Light’ mean different things. ‘Lite’ refers to the calorie content of a drink whereas ‘Light’ refers to alcohol content. You could easily, and unknowingly, be over the legal limit by drinking a beer labelled ‘Lite’.

The figures above, as stated, are based on a man weighing 68kg. Many women, and indeed some men, weigh less and so the time period or alcohol amount that can safely be consumed varies. Factors such as health, fitness, age, speed of drinking, food eaten, and even mood can also affect how people react to alcohol.

What happens when alcohol enters the body? A small amount is absorbed into the bloodstream via the mouth. Up to 20% is absorbed in the stomach. This can be slowed by fatty foods. Conversely, carbon dioxide – the bubbles in sparkling wines or in soda mixers – hastens absorption. The bulk of alcohol (80%) is absorbed into the bloodstream from the small intestine. It is carried by the bloodstream to all parts of the body, hence the intoxicating effect on the brain.

Alcohol is removed by metabolism in the liver at the rate of 0.02mg per hour. A tiny amount is lost via perspiration, urine or breath. In short, there are no short cuts. Time is the only way to use up alcohol and that is why you must restrict yourself to 1 standard unit of alcohol per hour. Remember too, that it is quite possible to be over the legal limit during the morning after a heavy night of drinking.

The effects on driving are significant. Your chances of an accident are doubled after only one unit of alcohol. It is estimated that 50% of people who die on our roads are over the legal limit. The penalties of being caught are severe too: fines of up to R120,000 or up to 6 months in prison.

The amount you drink is your responsibility and no one else’s. I hope you have read this far. I hope too that you have learned something that you didn’t know already. I have in writing this piece.

Stay safe. Drink responsibly!

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