PEOPLE who have a single pint risk being over the drink drive limit and losing their licence, according to experts.

Two independent drink drive experts concluded that one pint of beer was enough to put a driver over the limit when giving evidence at Blackburn Magistrates’ Court.

The findings came to light when a businessman was breathalysed after being reported as a possible drink driver.

Francis Riley’s breathalyser test measured 91 microgrammes of alcohol when police tested him after he had returned from a takeaway and was eating his meal with a glass of red wine. The legal limit is 35 microgrammes.

Forensic scientists for the prosecution and defence were asked to calculate his probable levels before drinking the wine. Both concluded he could have been over the limit after drinking the one pint of Cobra.

The beer has an abv – or ‘alcohol by volume’ – of five cent, the same as many other popular brands.

Experts said the findings would be a lesson for everyone who has a ‘swift one’ while waiting for their curry.

Dominic Harrison, director of public health for Blackburn with Darwen, said: “Drivers can’t assume that a pint will have the safe effect, even on the same person, because there are different factors that come into play, such as whether a person is tired, their gender, if they have a heavy cold and whether they have eaten.

“This judgement could have quite significant national implications and I hope it will underline the danger of drinking anything and driving.”

During the court case Andrew Stephens, the forensic expert engaged by the defence, said one pint of Cobra could have given a reading of between 26 and 49 microgrammes of alcohol in 100 millilitres of breath – against the 35mg limit. Mr Stephens said the most likely reading would have been 37 microgrammes.

James Haworth, the expert instructed by the prosecution, put the reading at between 27 and 42 microgrammes of alcohol but he gave the most likely level as 39 microgrammes.

Both based their calculations on the description of Riley, 49, of Smithy Row, Hurst Green, as a man of medium height and build.

Defending, Andrew Church-Taylor said: “Adding in all the factors the expert says at the time he was driving his reading would have been between 26 and 49 microgrammes of alcohol.

“It is not a precise science but the expert could not say with any certainty that he would have been under the limit having drunk one pint of Cobra at the restaurant. I was rather surprised to see one pint could give that kind of level and perhaps there is a lesson there for all of us.”

Riley pleaded guilty to driving with excess alcohol. He was fined £505 with £100 costs and banned for the minimum period of 12 months.