How accurate are home breathalysers?

drink driving ban

If you’ve had an alcoholic drink and are considering getting behind the wheel of the car, then it is often hard to know whether or not you are under the legal limit. Whether this is a drink you may have consumed earlier in the day, or maybe you’re planning on driving the morning after drinking the night before. Whatever the reason, it is often guesswork whether or not the alcohol has been broken down by the body sufficiently to avoid a drink driving ban.

There is a possible solution to this. It is possible to buy home breathalysers which can enable you to test whether or not it is safe to drive. But can these be relied upon? Are they accurate enough to trust?

Understanding what ‘good’ looks like for home breathalysers

It is generally accepted that these devices can vary a lot in terms of their overall effectiveness, so it is well worth doing your research before you commit to buying one. sums this up perfectly, in their assessment that “prices of breathalysers vary a great deal, as do their reliability, quality and accuracy”.

There are a number of variables that can affect the reading on a home breathalyser, so it is important to be aware of all of these before putting your trust in such a device.

What are the main factors that can affect how accurate home breathalysers are?

  • Whether or not it is used correctly
  • The make and model you have purchased
  • Whether or not there is ‘residual’ alcohol in the mouth

Reinforcing the amount of variation found between the different brands; gadget testing website, the Wirecutter, tested many different home breathalysers over a period of four years, comparing their readings with those taken by official police equipment. Their research considered reviews of over 100 home breathalysers, drawing up a shortlist and testing 15 different models.

If in any doubt – don’t drive

Although home breathalysers could be regarded as a helpful device to have on hand, the Wirecutter sensibly concludes “if you’ve been drinking enough to think about using a breathalyser to see if it’s safe for you to drive, you’re drunk enough that you should call a cab.” The information gleaned from a home breathalyser can act as a useful tool to understand how quickly your body breaks down alcohol, but the best rule of thumb to apply is that if you have had any form of alcoholic drink, it is always best to avoid the car.