Blood alcohol concentration (BAC)

The level of alcohol in the blood is measured in grams per litre of blood following a blood test or in milligrams per litre of exhaled air using a breathalyser.

Blood alcohol concentrations vary depending on:

• the quantity of alcohol that has been consumed,
• your weight: the lighter you are, the higher your blood alcohol concentration will be after drinking the same amount of alcohol,
• your sex: women are more sensitive to the effects of alcohol than men,
• how quickly you drink: drinking a lot of alcohol in a short space of time pushes up your blood alcohol concentration more quickly,
• what you have eaten: alcohol enters the bloodstream more quickly on an empty stomach.

Legal blood alcohol limit in Luxembourg

In Luxembourg, it is illegal to drive with a blood alcohol concentration of more than 0.5g of alcohol per litre of blood.

This limit was set at 0.2g of alcohol per litre of blood for:

• drivers below the age of 18,
• learner drivers,
• trainee drivers,
• driving instructors,
• people accompanying learner drivers,
• professional drivers.

A blood alcohol concentration greater than or equal to 1.2g of alcohol per litre of blood will result in the immediate loss of the person's driving licence.

Alcohol elimination time

Alcohol is broken down by your liver, and there is nothing that can speed up the process. It takes at least 1 hour for your liver to eliminate 1 glass of alcohol (the measure served in a bar or restaurant).

One glass of alcohol represents more or less the same quantity of alcohol. There is as much alcohol in a glass of beer as a glass of wine or champagne or a glass of whisky served in a bar or restaurant.

Remember that after a night of heavy drinking and a good night's sleep, the residual alcohol concentration in your blood might still be high: a blood alcohol concentration of 1.5g of alcohol per litre of blood at midnight could still be as high as 0.6g per litre by 09:00 the next morning.