ALCOHOL SCIENCE

Information taken from Handbook for the BIIAB Level 2 National Certificate for Personal Licence Holders 4th Edition June 2005

ABV AND UNITS

ABV is something you will see on any can or bottle containing an alcoholic drink.  It actually means “alcohol by volume”.  This means that whatever the ABV is, is the amount of alcohol in the drink.  So 37.5% of a bottle of vodka is alcohol.

Lots of people talk about units of alcohol but what does this mean.  One unit is 8 grams (g) of alcohol or 10 millilitres (ml) of alcohol.  So half a pint of 3.6% ABV beer contains about 8g of alcohol, so one unit.  25ml of whiskey at 40% ABV also contains 8g, so one unit again.

There is a calculation (a sum) that you can do to work out how many units you have had. You multiply (times) the amount you have drunk in millilitres(ml) by the alcohol by volume (abv shown as the %) by 0.001. So ml x abv x 0.001. Some examples are:

And just to let you know, on some bottles the amount in the bottle is not measured in millilitres (ml) but in centillitres (cl). Basically a cl is 10 ml so you can still use the sum above.

It takes the body about one hour to remove one unit of alcohol and there is no way of speeding it up.  Drinking black coffee, orange juice or pints of water are not a magical way of sobering up.

It is recommended that:

Men have no more than 3-4 units per day and no more than 21 in a week

Women have no more than 2-3 units per day and no more than 14 in a week

Binge drinking is classed as drinking more than 4 - 6 units in any session. But binge drinking can be just drinking too much for you in any one time.

SO HOW DOES ALCOHOL AFFECT THE BODY?

BAC (Blood Alcohol Concentration) is measured in milligrams (mg) of alcohol in millilitres (ml) of blood.  The following is a guide to how the body reacts the higher the BAC:

50	Feeling of warmth Skin flushed Impaired judgement Decreased inhibitions
100	Obvious intoxication in most people Increased impairment of judgement, inhibition, attention and control Some impairment of muscular performance, slowing of reflexes
150	Obvious intoxication in most people Staggering gait and other muscular in coordination Slurred speech Double vision Memory and comprehension loss
250	Extreme intoxication or stupor Reduced response to stimuli Inability to stand Vomiting Incontinence Sleepiness
350	Coma Unconsciousness Little response to stimuli Incontinence Low body temp Poor respiration Fall in blood pressure Clammy skin
500	Death likely

 

Drinking and Driving

80 mg in 100 ml of blood is the drink drive limit.  This can be measured in micrograms in ml of breath (35 micrograms in 100ml of breath)
                                               
“There is no simple way of knowing how much an individual can drink and stay within the legal limit to drive, or of knowing how the same amount of alcohol will affect different people”

The only safe way of knowing that you having drank to much is by not drinking at all.

And don't forget that alcohol takes a long time to leave your system, so if you drink at night you still might be over the limit the next morning.