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When alcohol enters your body, it must pass through the liver in order to be metabolized. Therefore, one or two beverages will leave your system long before a six-pack or more will. Because of this, if you know or suspect that an alcohol test may be coming up, it is best to abstain from drinking for one to two days before the test to ensure the best results and chances of passing. The average, healthy liver can process about one ounce of alcohol, or approximately one drink, per hour. Also, all alcohols are the same as far as your liver and the tests go. One beer is one shot is one glass of wine is one mixed spirit.
Read more: How Long Can Alcohol Be Detected in Your Urine? | eHow.com http://www.ehow.com/how-does_5435928_lon...
Beer stays in your body, on average, for one hour per unit. One pint of beer is equivalent to two units, unless it is strong beer. One pint of 5%-strength beer is 2.8 units. 6 beers would therefore stay in your body, on average, for at least 12 hours.
Alcohol is eliminated from the body by excretion and metabolism. Most alcohol is metabolised, in a similar manner to food, and a smaller amount is excreted. The rate that alcohol is metabolised depends on many factors. These include your weight, age, sex, stress levels, metabolic rate, how much food you have eaten, the type and strength of the alcohol and whether you are taking any medication. Liver function is also important. The liver can metabolise only a certain amount of alcohol per hour, regardless of the amount that has been consumed. Heavy drinkers’ livers are often impaired and metabolise at a much slower rate than a healthy liver.
There is a test available called the EtG (Ethyl Glucuronide) test, which can detect alcohol in urine for up to 80 hours. It is usually used to monitor alcohol consumption in individuals who are legally prohibited from drinking alcohol. It is expensive and is unlikely to be used for a standard drug screen test.
Don’t be tempted to tamper with a urinalysis drug screen, for example by dilution. Tests are often done to find out if the sample is legitimate and tampering will be deemed as having a positive result.