Alcohol is classed as a drug as when it is consumed it can alter the physical, mental and emotional state of the drinker. For the purposes of licencing law a Justices Licence is required for all drinks in excess of 0.5% alcohol by volume. Packaged drinks in excess of 1.2% must be labelled with their alcoholic content by volume.

There is a growing market for ‘alcohol free’ and ‘low alcohol’ drinks. To be classified as alcohol free a drink must contain no more than 0.05% abv and for low alcohol, the drink must contain no more than 1.2% abv and both types of drink must be labelled accordingly.

As many customers keep a sharp eye on their alcohol intake on a daily and weekly basis, this can be monitored by adding up the number of ‘units of alcohol’ digested.

A unit of alcohol is 8g or 10mm of alcohol. A half pint of 3.6% beer contains about 8g of alcohol and so is said to contain one unit of alcohol. One 25ml measure of 40% spirit also contains approximately one unit.

The effect that alcohol has on a person is determined by the amount of alcohol in their blood, which is known as the ‘blood alcohol concentration’ (BAC). BAC is measured in mg of alcohol in ml of blood. The current legal limit for driving is 80mg of alcohol in 100 ml of blood, which is equivalent to 35 micrograms of alcohol in 100 ml of breath.

The number of units of alcohol in a drink can be calculated by applying the following formula :

Amount of liquid in ml x % abv x 0.001 = units of alcohol contained For example, a pint of Yates Premium (5.2%) would contain : 568ml x 5.2% x 0.001 = 2.96 units of alcohol or a pint of Jennings Bitter (3.5%) would contain: 568ml x 3.5% x 0.001 = 1.99 units of alchhol

The speed of intake and concentration of alcohol in the bloodstream depends on such factors as :
Sex. The same drinks produce higher concentrations in females than in males.
Food consumed. The presence of food in the stomach slows down the rate at which alcohol passes through the stomach wall.
Body size. A small person has less blood than a large one and therefore the same drink will produce a higher level in a petit person.

There is no simple way of determining how much can be drunk and knowing that one is within the legal limits. Far better not to drink and drive. Alcohol is obviously broken down by the body and eliminated. This rate is approximately one unit of alcohol per hour. There is no way of speeding up this process.

Hugh Price, MBII

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