Drinking one pint of beer or one glass of wine could put you over the limit for drink driving, the Medical Bureau of Road Safety warned as a Christmas and New Year safety appeal is launched today.
Prof Denis Cusack, director of the bureau, said it wants people to enjoy themselves but to be aware that there are “very serious dangers” in drinking and driving.
"If you've been out drinking until two or three in the morning, there's a big risk, particularly if you're a learner driver or a novice driver where the limit is 20 (20mg of alcohol per 100ml of blood), not only of being caught but also of being in an accident and causing injury or killing somebody," he told RTÉ's Morning Ireland.
“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.”
Prof Cusack explained the Medical Bureau of Road Safety is the national laboratory that analyses specimens of blood, urine and breath in alcohol and drugs and provides the equipment people see at roadside stops and in Garda stations.
“We ensure every single device is checked again and again; we are prepared to stand over them and their results.”
He warned it is very difficult for people to estimate the amount of alcohol they have in their body. “The human body is a fantastic machine - it has to work in a certain way, so when we take in a drink, we’ve got to handle it in the body and then get rid of it.
“One of the difficulties is you’ve almost got to be an expert in alcohol because beer, wine, spirits, liquors - they all have different alcohol concentrations,” he said.
“How much you drink, how quickly you drink it, whether you mix beer and spirits, whether you’ve had a meal, your weight, your obesity, fat cells, also whether you’ve taken food with it, and, indeed, how used you are to taking alcohol - all of these go together.
“The advice really is, the bottom line is, don’t drink and drive. It’s very, very difficult to estimate how much is in your body.”
Prof Cusack said people buying over-the-counter “morning after” remedies think these will help dissipate the effect of alcohol but added this is not the case.
“Our bodies can only handle and get rid of alcohol, we get rid of approximately half a pint or a glass of wine every hour. So if you take two pints it’s going to take four hours to get rid of that from your system.
“It takes an hour to get most drinks from your system. However, people rarely keep tabs on how much they’ve been drinking, when you keep on adding every 15 minutes, half an hour, it’s impossible to calculate,” Prof Cusack said.
“The bottom line is, don’t drink and drive.”