We have been experiencing some glorious weather over the last few weeks here in Ireland. Sunshine, clear skies and most surprisingly, little to no rain which means going out and having a beer with friends in a pub’s outdoor area is quite feasible. While a friend and I were out last week, basking in the sun and chatting over a few pints (one alcoholic and one non-alcoholic) the conversation led to how non-alcoholic beer does not impair a drinker’s ability to drive, or send them over the drunk driving limit, even if they contain trace elements of alcohol. I must admit, I had some idea as to why, but when I got home (having driven safely) I decided to research the question further.

The designated driver seems like a blessing on nights out or at social events where peers are drinking alcohol. Imagine having a great night out with friends then being dropped safely to your door, avoiding having to catch a taxi, bus, or tram. No more queuing at taxi ranks in the cold, making awkward chit chat with the driver (“So, you out long bud?”) and then having to pay for the experience. Non-alcoholic beer producers have become aware of this demographic and aimed marketing campaigns at the designated driver. One of the most notable was in 2018 when Heineken 0.0 launched and directed promotions towards both the health-conscious and drivers alike.

The wide spectrum of non-alcoholic beers in today’s market can range from 0.0%- 0.5% alcohol by volume (ABV). One would be forgiven for thinking enough beers, particularly of the 0.5% strength could affect inhibitions and ability to drive safely. So, why is this not the case? A good starting point would be to examine current Irish legislation relating to the offence of drunk driving. Drunk driving is measured by measuring blood alcohol concentration (BAC) levels. At present, The Road Traffic (Amendment) Act 2018 sets the legal limits as:

  • 20 milligrams of alcohol per 100 millilitres of blood for learner and novice drivers.
  • 50 milligrams of alcohol per 100 millilitres of blood for fully licensed drivers.

This is perhaps better explained using units of alcohol. One standard unit is approximately 10ml or 8g of pure alcohol. A simple and useful formula for calculating the number of units in one drink is:

Strength of Drink (ABV) x ml/1000= No. of Units.

Therefore, one pint of beer with an abv of 0.5 is calculated as:

0.5 x 568/1000= 0.284 Units (0.284/8= 2.27g)

Hence, 1 unit is 3.52 pints of beer with 0.5% ABV (8g/2.27). Given a healthy liver will process one unit of alcohol (half a pint of standard beer) in an hour one pint of such beer is processed in approximately 17 minutes. This would mean having to drink a lot of beer in a short space of time to even push these limits. A 2012 study published by Germany’s University of Freiburg concluded that “even with forced consumption of non-alcoholic beer, no negative legal consequences are to be expected for novice drivers”.

The experiment consisted of 78 participants who had abstained from alcohol for five days prior then consume 1.5 litres of beer with an ABV of 0.4% in under an hour. Their BAC was measured between 15–30-minute intervals. The highest reading obtained was a concentration of 0.0056%. This result appeared to be an outlier and is considerably high in comparison with other test subjects as the participant in question was a 75-year-old man. It was concluded that older people have a lower body water volume as this figure decreases with age. However after “30 minutes after the end of drinking all samples were ethanol-negative with a detection limit of 0.0005 g / l”. This demonstrates that while there are some variables (age and weight) that can cause non-alcoholic beer to affect the drinker’s BAC levels, the body has an ability to process it at a rapid level, making it highly unlikely to cause a driver to be over the drink driving limit, and if they are it is for a very short period. One key element to do experiment’s results which cannot be overlooked is that the volume of beer consumed, 1.5 litres in an hour seemed quite high and would be difficult, if not next to impossible, to maintain over an extended period.

So back to the Irish law, if we take the lower threshold of learner drivers whose limit is “20 milligrams of alcohol per 100 millilitres of blood” how much beer would cause them to be above the limit? This proved quite a contentious amount to work out and to obtain an exact, quantitative figure, but it could be best explained by Prof. Denis Cusack, Director of Ireland’s Medical Bureau of Road Safety of who stated, “One pint of beer or one glass of wine could put you over the limit, especially novice or professional drivers where the limit is 20/100”.

What about breathalyser testing? Despite its name, a breathalyser does not take a sample of one’s breath but rather the air produced from their lungs. For alcohol to enter the lungs it first must pass through the bloodstream. As stated above, this would require a massive quantity or number of non-alcoholic pints of beer to occur. To put it simply, non-alcoholic beer cannot set off breathalyser tests, even if the beer contains minute traces of alcohol, unless of course, as stated above, you consume an extreme volume over a short space of time

So, let’s raise a glass to non-alcoholic beer, the perfect drink for the designated driver and also the health-conscious drinker, mindful of his or her unit of alcohol intake.  

Cheers!