We test how much you can drink before being over the legal limit to drive in South Africa

You can drink around 500ml of beer and still be under the legal limit to drive your car in South Africa, provided the drink’s alcohol percentage is no higher than 4%.

TopAuto recently put 12 people to the test to see how much they have to drink before being over the limit, and recorded their Breath-Alcohol Content (BAC) using a high-quality breathalyser.

We found that while the reading varies significantly between persons, the majority of participants blew under the legal limit of 0.24mg of alcohol per 1,000ml of breath (0.024) after having 500ml of a popular local beer with 4% alcohol content – with only two out of 12 being over the limit after this level of consumption.

Methodology

To perform this test, we gathered 12 willing participants of all shapes and sizes and tested their BAC at set intervals over three days and at three different levels of consumption.

According to the South African Police (SAPS), most people will be over the limit after drinking 350ml of beer or cider.

As such, just in case 350ml would have put us well over the maximum, we tested the BAC of all 12 participants at 200ml on the first, 350ml on the second, and 500ml on the last day- the latter of which is the average volume of one draught beer at most bars and restaurants.

The BAC readings were measured around two hours after all the participants had the same meal, and approximately 30 minutes after they finished their drinks to allow excess vapours that lingered around in their mouths to disappear for a more accurate reading.

For each test at each consumption level, two readings were taken per participant, and the average of those used for the BAC score.

The 12 participants’ body measurements were as follows:

The breathalyser used was the BACtrack Element, which is available on Amazon for $84.99 (R1,650) and is certified for accuracy to three decimal points by the United States Department of Transport and the National Highway Traffic Safety Administration.

The device operates through fuel-cell sensors consisting of two platinum electrodes that oxidize the alcohol in a breath sample and produce an electrical current that the breathalyser measures to determine the BAC.

Results

We found that BAC levels vary significantly from person to person depending on their height, weight, fitness, and gender, with smaller individuals and women being the most affected by alcohol. However, the majority of people regardless of their gender or size will still blow under the legal limit after drinking the SAPS-recommended 350ml of beer.

After having 200ml of beer and waiting roughly 30 minutes, all the participants registered a 0.000 BAC reading. After 350ml, exactly half of the participants remained at 0.000 BAC while the rest ranged between 0.008 and 0.016, still well below the legal limit of 0.024.

After 500ml, every participant had a tangible reading, ranging from as low as 0.007 to as high as 0.030 – with only two people exceeding the maximum allowed BAC.

“Tolerance” played no role, either, with self-professed avid drinkers and those who barely sip on alcohol displaying more or less the same readings at the same consumption levels.

Considering many participants blew close to 0.024 after drinking 500ml, a beer with a higher alcohol percentage than 4% would likely put a large portion of people in South Africa over the legal limit after one 500ml draught.

Therefore, if you do go out to have a cold one and you suspect you might have overstepped the legal bounds but still have your wits about you, it’s best to wait it out for at least half an hour and have something to eat or a non-alcoholic drink to reduce its cognitive impact and the chances that it will be picked up on a breathalyser.

Better yet, refrain from drinking and driving completely and use a ride-hailing service or a designated driver if you know you’ll be having a few alcoholic beverages.

Drinking alcohol slows down your reaction time regardless of how much you had, and makes something that is already highly dangerous – driving in South Africa – even more so.

The table below shows the BAC levels of all 12 participants at varying levels of consumption:

This article does not condone nor encourage drinking and driving, it is incredibly dangerous and puts not only your life but those of everyone around you at risk.

Keyword: We test how much you can drink before being over the legal limit to drive in South Africa