One of the most common ways of finding out how much alcohol is in a person’s blood is by measuring their Blood Alcohol Concentration (BAC).
What Is BAC (Blood Alcohol Concentration)?
Blood alcohol concentration (BAC) is a method of analysing how much alcohol is in the blood. This, as opposed to measuring the exact amount of alcohol the person has drank, will influence how alcohol affects the individual’s brain, body and behaviour.
How is BAC (Blood Alcohol Concentration) measured?
Alcohol in the bloodstream is measure by the amount of alcohol that is present in a 100 milliliter (mL) volume of blood. It is usually shown as a decimal, such as 0.08%. In this case, 0.08% refers to 80mg of alcohol. This can also be described as 0.08 BAC
What is the legal driving limit for BAC in the UK?
In England and Wales, the legal limit for drivers is 80 mg of alcohol per 100 ml of blood. This equates to 35µg (microgrammes) per 100 m for breath alcohol and 107 mg per 100 ml for alcohol in urine.
In Scotland the drink driving limit was reduced in November 2014. North of the border the limit is now 50 mg or 0.05%. This brings Scotland in line with most of the rest of Europe. Northern Ireland is also expected to follow suit in early 2015.
How much can I drink and still be under the drink driving limit?
It is common perception that a BAC of 0.08% is roughly equivalent to two pints of normal strength beer for a man of average weight. This crude calculation should not generally be used as there is no accurate correlation between the peak level of BAC and the amount of alcohol consumed.
There is a good chance that anybody trying to “drink up to the limit” will run a serious risk of exceeding it. A more scientific method, if you need on the spot testing for blood alcohol level, is a breath alcohol detector. This kind of device is a single use breath alcohol test, which can be useful in a variety of situations.