The 0,05 blood alcohol limit is the figure most South African drivers have heard of, but very few can explain what it actually means in terms of the glass in front of them. Ask how many drinks it takes to reach 0,05 grams of alcohol per 100 millilitres of blood and the honest answer is that there is no fixed number. The same drink that leaves one driver well under the limit can push another driver over it.
That uncertainty is precisely why the South African limit is framed as a concentration in blood or breath, and not as a count of beers or glasses of wine. Body weight, biological sex, age, liver function, food in the stomach, the strength of the drink, and the speed at which it is consumed all change how alcohol is absorbed and cleared. This article explains what 0,05 means in law, why no drink count can be relied on, and why the only safe choice before driving is not to drink at all.
What the 0,05 Limit Actually Means in South African Law
Section 65 of the National Road Traffic Act 93 of 1996 sets the legal alcohol limits for drivers on South African roads. For an ordinary driver, the limit is a blood alcohol concentration of not more than 0,05 grams per 100 millilitres of blood, or, where a breath test is used, not more than 0,24 milligrams of alcohol per 1 000 millilitres of breath. The two figures describe the same threshold measured in different ways.
For professional drivers, such as the holders of public driving permits, the limit is far stricter at 0,02 grams per 100 millilitres of blood. The same section also makes it an offence to drive while under the influence of intoxicating alchohol liquor, which means the State can prosecute on observed impairment even where no reading is taken. A driver who feels sober can still be over the limit, and a driver who is under the limit can still be charged if the officer’s evidence of impairment is accepted.
Why There Is No Safe Number of Drinks
The reason no two sources agree on how many drinks reach 0,05 is that the answer depends on the individual. Alcohol is distributed through the body’s water, so a larger body generally produces a lower reading from the same amount of alcohol. Women typically reach a higher blood alcohol concentration than men after the same dose, because of differences in body composition and in the enzymes that break alcohol down. Age, medication, fatigue, and liver health all add further variation.
What is in the glass matters as much as who is drinking it. A “standard drink” is often described as roughly 14 grams of pure alcohol, which is close to a 350 ml beer at average strength, a 120 ml glass of wine, or a single 25 ml tot of spirits. But South African beers, wines, and cocktails vary widely in strength and serving size, and a single large craft beer or generous glass of wine can contain the alcohol of two standard drinks without looking out of the ordinary.
- Body weight and composition. A smaller body has less blood volume to dilute the same amount of alcohol.
- Biological sex. Differences in water content and enzyme activity usually mean a higher reading for women from the same dose.
- Food in the stomach. Eating before or while drinking slows absorption but does not stop it, and the alcohol still has to be cleared.
- Speed of drinking. Two drinks in twenty minutes produce a much higher peak than two drinks over three hours.
- Drink strength and pour size. A heavy pour at home or a cocktail with multiple shots can double the alcohol in a single glass.
Because of these variables, rough guides that suggest “two drinks an hour is fine” are misleading. For some drivers, a single drink is enough to approach or cross 0,05, particularly on an empty stomach or with a strong pour. Counting drinks is not a reliable way to stay under the legal limit, and the only way to be certain of driving legally is not to drink before driving at all.
How the Body Processes Alcohol
Once alcohol is in the bloodstream, the liver does almost all of the work of removing it, at a fairly steady rate of roughly one standard drink per hour. Coffee, water, fresh air, and a cold shower may make a driver feel more alert, but they do not speed up the liver. This is why “sleeping it off” for an hour or two is no guarantee that a reading has fallen below 0,05, and why drivers are often surprised by a breathalyzer reading the morning after a heavy night.
The reading also keeps rising for a period after the last sip, because alcohol continues to absorb from the stomach and intestines into the blood. A driver who feels fine immediately after finishing a drink may actually peak ten or twenty minutes later. This lag is one of the reasons the police wait before taking an evidential sample, and it is another reason that counting drinks against a clock is unreliable.
The Effects of Alcohol on Driving at 0,05
By the time a driver reaches 0,05, measurable impairment is already present, even where it is not felt. Tracking a moving vehicle, judging following distance, and recovering from glare all become less reliable. Reaction time slows, and the driver tends to fixate on a single point rather than scanning the road.
- Reduced ability to divide attention between the road, mirrors, and traffic signs.
- Slower reaction to sudden hazards such as a pedestrian stepping out or a vehicle braking.
- Impaired coordination of steering and pedal use.
- Poorer judgment of speed and distance, and a greater willingness to take risks.
The danger is that confidence tends to rise as skill falls. Alcohol produces a misplaced sense of being in control, which is exactly why self-assessment after drinking is so unreliable. A driver who feels “fine to drive” may already be over 0,05 and already impaired.
The Legal Consequences of Crossing the Limit
Driving with a blood or breath alcohol concentration above 0,05 is a criminal offence in South Africa, not a traffic infringement. A conviction can carry a fine or imprisonment, or both, and it leaves the accused with a criminal record. The court may also endorse or suspend the driving licence, and the consequences of a record can extend to employment, travel, professional registration, and firearm licensing.
Where the driving is alleged to have been reckless or negligent, or where injury or death results, the State often lays the more serious charges of reckless or negligent driving, or culpable homicide, alongside the alcohol charge. Our guidance on the sets out sentencing in more detail.
An arrest for driving over the limit usually begins at a roadblock and leads to a breath or blood sample at a police station, followed by detention and a court appearance. The procedure around the test, the chain of custody for the sample, and the accused’s rights under section 35 of the Constitution all matter to the outcome, and these are questions best examined by a criminal defence attorney as early as possible after arrest.
Frequently Asked Questions
How many drinks reach a 0.05 blood alcohol level?
There is no fixed number. The drinks it takes to reach 0,05 grams per 100 millilitres of blood vary with body weight, biological sex, age, food in the stomach, the strength of the drink, and the speed of drinking. For some drivers a single standard drink can come close to the limit, which is why South African law sets the threshold as a blood or breath concentration rather than a drink count.
What is the legal blood alcohol limit for drivers in South Africa?
Under section 65 of the National Road Traffic Act 93 of 1996, an ordinary driver may not exceed 0,05 grams of alcohol per 100 millilitres of blood, or 0,24 milligrams of alcohol per 1 000 millilitres of breath. For professional drivers the limit is 0,02 grams per 100 millilitres of blood.
Can food or coffee lower your blood alcohol concentration?
No. Eating before or while drinking can slow how fast alcohol is absorbed, but it does not reduce the total amount that reaches the blood. Coffee, water, fresh air, and a cold shower may make a driver feel more alert, but only time, as the liver processes the alcohol, lowers the concentration.
How long does it take for blood alcohol to fall below 0.05?
The liver removes alcohol at roughly one standard drink per hour, and the reading can continue to rise for a short time after the last drink. There is no reliable shortcut, and a driver who has drunk heavily may still be over the limit the following morning. The only safe choice before driving is not to drink at all.
Is driving at 0.05 blood alcohol a criminal offence in South Africa?
Yes. Driving with a blood or breath alcohol concentration above the limit set by section 65 of the National Road Traffic Act is a criminal offence. A conviction can result in a fine or imprisonment, a criminal record, and endorsement or suspension of the driving licence.
Get help with a criminal law matter. If you have been arrested, or you are facing a charge of driving under the influence, the Criminal Law department at Otrebski Attorneys can advise you from the police station through to the court process. We are a 100% women-led firm with a Level 4 B-BBEE rating, rated 5 stars across 12 reviews, based from our single Sandton office, and our Director Nastasja Otrebski leads the team that defends motorists across South Africa.
Disclaimer. This article is general information about South African road traffic and criminal law, not legal advice for a specific matter. Blood and breath alcohol limits, evidential procedures, and sentencing outcomes depend on the facts of each case and on current court practice. For advice about a particular charge, consult a qualified attorney or Legal Aid South Africa.