Blood Alcohol Concentration (BAC)
PDF 80 KB
Many people consider alcohol to be part of the Australian culture and way of life. But drinking doesn’t always equate to a good time.
There are harms associated with drinking too much both on a single occasion and over a lifetime. These can be serious and even life threatening.
Statistics show that the serious consequences caused by drinking too much on a single occasion generally fall into three categories:
There are three guidelines to reduce health risks from drinking alcohol.
If four or more standard drinks put you at risk of injury, it makes sense that it may also put you and the people around you at risk of legal and social consequences.
Although it varies between individuals, there is a relationship between the concentration of alcohol in the blood (Blood Alcohol Concentration) and its effects.
The body will only process around one standard drink per hour. This means, for every standard drink you have, it will take one hour for your BAC to return back to 0.00g%.
Alcohol starts to affect the brain within five minutes of being consumed. The blood alcohol concentration (BAC) peaks about 30 to 45 minutes after one standard drink is consumed. Rapid consumption of multiple drinks results in a higher BAC because on average, a person can only break down one standard drink per hour.
The effects of alcohol vary depending on a number of factors including:
To reduce risk when drinking, the most important point to remember is to not drink more than the levels recommended in the national guidelines. On a single occasion of drinking, the risk of alcohol-related injury increases with the amount consumed.
For healthy men and women, drinking no more than four standard drinks on a single occasion reduces the risk of alcohol-related injury arising from that occasion.
Keep in mind that having four standard drinks doubles your risk of an alcohol-related injury and your risk increases with every extra drink you have. This risk is even higher in younger people.
The lifetime risk of harm from drinking alcohol increases with the amount consumed.
The national guidelines state that for healthy men and women, drinking no more than ten standard drinks a week reduces the lifetime risk of harm from alcohol-related disease or injury.
The same health/safety, legal and social harms associated with drinking too much on a single occasion apply to lifetime drinking. But as well as these harms, drinking more than recommended in the national guidelines on an ongoing basis increases the risk of a number of diseases and adverse effects that reduce quality of life and cause premature death.
Alcohol-related health issues include:
SA Health offers a range of public health services for people with alcohol related problems and their family and friends.
Community-based and inpatient and residential treatment services are available. Community-based services are also available in country areas.
There are also a number of private alcohol related health services available.
Telephone the Alcohol and Drug Information Service on 1300 13 1340 for details.
Tolerance means a person requires more alcohol to achieve the same effect they used to get with smaller quantities because the brain compensates for the sedating effects of alcohol and the liver breaks it down more quickly. Despite this tolerance, the risk of long-term effects remain.
A person has alcohol dependence when its use has become central in their life. A lot of time is spent thinking about alcohol, obtaining it, using it and recovering from its effects. Use is continued despite knowing that it is causing harm.
A common feature of dependence is that a person will experience withdrawal symptoms if they reduce or stop drinking due to increased excitability (irritability) of the brain.
Typical alcohol withdrawal features last about five days and include:
People drinking eight or more standard drinks per day are advised to discuss a decision to stop drinking with their doctor as medication may be needed to prevent withdrawal complications such as seizures.
People who regularly drink alcohol at harmful levels have an increased risk of brain damage including dementia.
To reduce the risk of harm from alcohol-related disease or injury, healthy men and women should drink no more than 10 standard drinks a week and no more than 4 standard drinks on any one day.
The less you drink, the lower your risk of harm from alcohol.
To reduce the risk of injury and other harms to health, children and people under 18 years of age should not drink alcohol.
The guidelines and supporting resources are available at: www.nhmrc.gov.au/alcohol.