How long does alcohol stay in your system?

The Christmas party season is officially upon us. For some, this includes lots of festive drinks with family and friends.

Whilst most motorists would never dream of driving home after a night out on the booze, many may be running the risk of being over the drink-drive limit by getting behind the wheel the morning after.

Research by Think!, revealed that 58% of those surveyed would have four or more drinks on a night out and still take the risk by driving the following morning – with only 33% being aware they could still be over the limit. Department for Transport statistics show that drink-drive related accidents accounted for 13% of all deaths in road accidents in 2016, so raising awareness is key.

Swinton research found only 1 in 10 British drivers knew the legal alcohol limit for driving, do you?

In England, Wales and Northern Ireland, the alcohol limit for drivers is 80mg of alcohol per 100ml of blood, often referred to as 0.08 BAC (blood alcohol concentration).

In 2014, Scotland lowered its drink-drive limit to 0.05 BAC, which is in line with recommendations from the European Commission.

How long does alcohol stay in your system?

Alcohol can take much longer than people think to pass through the body. The NHS states it takes one hour on average to process a unit of alcohol, although this can vary depending on a number of factors including:

  • Weight and height
  • Gender and age
  • Metabolism
  • Fat/muscle content
  • Stress levels
  • How much food you have eaten
  • Whether you are on any medication

The NHS advises there are roughly:

  • 2.1 units in a 175ml glass of wine of average strength (12%)
  • 3 units in a 250ml glass of wine of average strength (12%)
  • 2 units in one pint of low-strength lager, beer or cider (3.6%)
  • 3 units in one pint of high-strength lager, beer or cider (5.2%)
  • 1.5 units in a 125ml glass of Prosecco (12%)
  • 1 unit in one single measure of spirits

To put it into context, if you drank two glasses of Prosecco plus four large (250ml) glasses of wine on a Christmas night out, you would have consumed roughly 15 units. After going to bed at midnight, if you set off the next day at 8am, it is likely you would still have around 7 units of alcohol in your bloodstream.

How alcohol affects your ability to drive?

A 2014 study in the US indicated that drivers were 13 times more likely to be involved in a fatal collision if they were above the 0.08 BAC limit. Even at 0.05 BAC (which would mean you were under the limit in England, Wales and Northern Ireland), you were still five times more likely to have a fatal collision.

Any amount of alcohol in your bloodstream can impact your driving ability, putting you at risk for causing an accident. Driving requires the ability to concentrate, make good judgements and quickly react to situations. However, alcohol affects these skills, putting yourself and others in danger.

Here are several ways alcohol impairs your driving skills:

Drink drive effects

The Guardian reported that in an old study, bus drivers were given different amounts of whisky to consume, and then given the challenge to drive their buses (off road of course!) between a pair of white posts. These posts were gradually brought closer together.

Initially, there was little difference in how well the bus drivers could navigate their way between the posts. But when the gap became narrower than the bus, those who were sober stopped, while those who had had a drink tried to drive through anyway. This demonstrates how much effect alcohol has on judgement.

Can I speed up the process of getting rid of the alcohol in my system?

The process of your body getting rid of the alcohol includes a mixture of mechanisms, mostly enzymes in the liver breaking the alcohol down. A process that can take longer if the liver is damaged or not working properly.
Whilst food may help ‘sober you up’, this will not speed the rate of how long it takes for alcohol to leave your system.

What’s the punishment for drink-driving?

Driving under the influence of alcohol is a serious offence and if you are found to be over the limit you could face strict penalties.

The exact penalty will depend on your offence and decided by the magistrates who hear your case. If you are found guilty, you will be given a hefty fine and banned from driving for at least 12 months. You can also be given between 3 to 11 penalty driving points and there is a possibility that you could be sent to prison for up to six months.

In some cases, you may be able to reduce your ban by taking a drink-drive rehabilitation scheme (DDRS) course.

If in doubt…

With such huge and potentially catastrophic consequences on the line, if you are in doubt whether you are over the limit, it is always best to not drive.

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