New research indicates some people may be physically unable to use police breathalysers

Some people may be physically unable to use the current evidential breath analysis machines, relied upon by police to gather proof of driving under the influence of alcohol or drugs, new research from the University of Sheffield indicates.

The new study challenges the norm that anyone failing to provide a sample of breath at a police station is being deliberately obstructive, questioning the fairness of ‘failure to provide’ charges.

Under the 1988 Road Traffic Act, anyone unable to complete a breathalyser test at a police station is automatically charged with Failure to Provide, which can have serious consequences for the offender including driving disqualifications, a maximum possible sentence of six months’ imprisonment and an unlimited fine.



What did the researchers discover?

The general assumption of the police and the courts is that those who fail to provide a breath specimen are wilfully failing to do so but evidence for this assumption is extremely thin.

The literature search revealed only four research papers pertaining to the current evidential machines and there are difficulties with each of these because of small samples, little detailed analysis or commentary, and risk of bias.

The researchers noted four characteristics that may impact on a person’s ability to give a breath sample: stature, age, sex and whether or not they smoke.


The researchers concluded:

Effects of stature

It is very clear from the BioBank data that shorter persons are at greater risk of being unable to provide a breath sample:


Effects of age

Age is an important factor:


Effect of sex

The sex of the person clearly emerges as critical factor:


Effects of smoking

No previous study has investigated the effects of smoking tobacco despite its well-known deleterious effects upon lung function. The present investigation confirms its relevance:



This study implies that, overall, at least 1 man in 186 and 1 woman in 61 would be physiologically incapable of providing an evidential breath sample and these figures can be approximately halved to 1 man in 87 or 1 woman in 32 if they happen to be daily smokers.

Age increases risk, with people in their 70 s being six times more likely to fail than those in their 40s. With regard to stature, the risk figures rise to 1 in 38 short men and 1 in 26 short women (i.e. below the second percentile of height), with increasing age further compounding this effect.

There are around 4000 annual prosecutions in the UK for Failure to Provide under the 1988 Act. If, as the results imply, a percentage of the population are physiologically incapable of operating the machines currently used, then some of these annual prosecutions may have had a wrong outcome – some individuals who should have actually received a penalty for driving under the influence of alcohol may have been acquitted when a different specimen would have proved their guilt, whilst other individuals who were not, in fact, over the legal limit may have been wrongly convicted of Failure to Provide simply because they were unable to use the machine.

It is not possible to estimate the actual number of unsafe convictions without detailed demographic information (age, sex, height, smoking status) regarding those who were prosecuted.


Is there an easy fix?

Correcting this situation would not require legislation but merely alterations to existing procedures, as the 1988 Act allows for a person to give an alternative sample if “the constable who required the specimens of breath has reasonable cause to believe that the device has not produced a reliable indication” or if “it is then for any other reason not practicable to use such a device”.

It would be helpful if police forces were alerted to the fact that certain people are unable to use the existing evidential machines and adopt a more flexible approach in allowing an alternative sample to be taken.


How can we help?

We have over 30 years’ experience of advising clients in connection with all motoring offences including drink driving offences and failure to provide a specimen. Our lawyers are up to date with the latest research, changes in the law and case law so that you can rely on us to help you achieve the best outcome possible.

If you are facing investigation or prosecution for any road traffic offence, please contact us as soon as possible on 0121 605 6000 or email us for further information.