The BAC measures the parts of blood, which consist of alcohol. You have heard of readings, like 0.04 and 0.08, all of these are less than 1% of your blood. For example, if you blow a BAC of 0.04, it means you have 4 parts (grams) alcohol for every 10,000 parts (grams) blood.
Number of Drinks: 2
⇒ Two American standard drinks will, on average, produce a Blood Alcohol Content of about 0.04, and most light and moderate drinkers will feel relaxed at this level.
A BAC of 0.0 is sober; in different countries the maximum permitted BAC when driving ranges from about 0.02% to 0.08%; BAC levels over 0.08% are considered impaired; above 0.40% is potentially fatal.
The general rule of thumb is that 2 standard drinks in the first hour will raise your BAC to 0.05%, and 1 standard per hour thereafter will maintain that level. To do a quick calculation of whether you are over 0.05% BAC, simply take the number of hours since your first drink and add 1 to it.
0.01 – 0.04 – Starting to Feel Relaxed and Less Alert
Between 0.01 and 0.04 is when most people begin to notice the effects of alcohol. It's important to remember that anything above 0.00 is illegal when someone is underage. That means blowing an 0.01 will still land them a DUI.
BAC 0.02%: At this percentage, you may experience an altered mood, relaxation and a slight loss of judgment.
Even with a BAC of 0.02, which is equivalent to about two drinks, your body will become more relaxed, and your judgment will begin to waver. If you're driving, you may experience a decline in visual function, and you may have trouble multitasking.
A BAC of up to 0.05 g% is likely to cause a feeling of wellbeing. Likely effects are being talkative, more relaxed and more confident. A BAC of 0.05 to 0.08 g% is likely to make you at risk of impaired judgment and reduced inhibitions. A BAC of 0.08 to 0.15 g% is likely to put you in a risky state.
Even if you're below 0.05% BAC, your judgement, reaction times and driving skills are impacted. A BAC 0.05% and above significantly increases the risk of car crash and fatality.
This means that 'alcohol-free' beers can contain a very small amount of alcohol. But how much is 0.05% ABV? To give you some context, a pint (568ml) of 1% ABV beer contains just over half a unit of alcohol[1], which is why 0.05% ABV drinks can be labelled as alcohol-free.
Blood alcohol concentration, or BAC, is the amount of alcohol in a person's blood. For example, if the BAC is 0.05%, that means the person has 50 milligrams of alcohol in 100 millitres of blood. How much and how fast a person drinks, their body weight and type, and how much food they have eaten affects BAC.
0.13 – 0.15% – At this point, your blood alcohol level is quite high. You'll be affected by blurred vision, loss of coordination and balance, and potentially dysphoria (anxiety or restlessness). 0.16 – 0.19% – The term “sloppy drunk” applies.
Your BAC measures the amount of alcohol you have in your system in grams of alcohol per 100 millilitres of blood. A BAC of 0.05 means you have 0.05 grams (50 milligrams) of alcohol in every 100 millilitres of blood.
Alcohol detection tests can measure alcohol in the blood for up to 12 hours, on the breath for 12 to 24 hours, urine for 12-24 hours (72 or more hours after heavier use), saliva for up to 12 hours, and hair for up to 90 days. The half-life of alcohol is between 4-5 hours.
In some cases, the breathalyzer may detect alcohol for up to 12 hours. In other individuals, the breathalyzer test may work for twice that long. Although the average person metabolizes about 1 alcoholic drink per hour, this rate varies.
How long does alcohol stay in your system to be detected by a breathalyser? The device can trace alcohol within 20 minutes from consumption and up to 12 hours later. For example, if your BAC is 0.02%, you could sober up after two hours.
What Is A High Breathalyzer Reading? In 49 states, a high breathalyzer rating is anything over 0.08%. In Utah, the legal limit is 0.05%. Individuals are not permitted to drive when over this blood alcohol content level and may be charged and sentenced with a DUI or DWI if they are caught.
With insignificant amounts of alcohol and fewer calories, it's clear that drinking alcohol-free beer (up to 0.5% ABV) is better than opting for an alcohol-laden equivalent and great for giving your liver a rest.
Generally, one green band means your BAC is under 0.05%, which is within the legal limit to drive. Two green bands indicate that your BAC is between 0.05% and 0.10%, and three bands means it's over 0.10%. You can buy either type of test for yourself if you want to make sure you're safe before you get behind the wheel.
Generally, for a person of average weight, drinking two standard beers within one hour may result in a BAC between 0.02 and 0.05. However, this estimation can vary significantly based on personal factors and should not be considered a definitive guideline.
Blood alcohol concentration
In the United States, a BAC level of 0.08% is the standard to identify legal intoxication. However, some states have additional standards, such as a BAC lowered to 0.04% for drivers of commercial vehicles. Many states impose harsh penalties for drivers whose BAC is exceptionally high.
A general rule of thumb is not to drive if you feel even the slightest effects of drinking. If you must take a drink or two, remember that our bodies metabolize one drink per hour. You might feel like you're good to go if you wait a few hours after drinking, especially if you dilute the alcohol by drinking water.
Generally, a breathalyzer test can test positive for alcohol for up to 12 hours after consuming one alcoholic drink. The average urine test can also detect alcohol 12-48 hours later. If your BAC is 0.08, it will take approximately 5 hours to metabolize the alcohol completely before you can become “sober” again.
These devices sometimes register “interfering substances.” If this happens the test is aborted and a blood sample is required. The maximum level of alcohol that may be accurately detected by evidential breath testers is 220 μg/100 ml air.
The Codes define 'low alcohol' drinks as being stronger than 0.5% ABV up to and including 1.2% ABV. Drinks that are stronger than 1.2% ABV but lower than the average drink of the same type may not be marketed as 'low alcohol'.