How Urine Testing Works
One popular form of urine testing uses a machine to look for traces of a substance called ethyl glucuronide, or EtG. This substance is created as the body starts to break down and digest alcohol. The test measures how much EtG is in the urine. This level is then correlated to a blood alcohol level. The problem is that EtG can appear in urine for a number of reasons. It can appear because of certain foods, cosmetics or even working around industrial chemicals. Additionally, it can stay in the urine for a long time. This means that EtG testing is not really a reliable way to determine whether a person is currently intoxicated.
The main problem with using urine testing to measure blood alcohol levels is that the numbers are frequently inaccurate. One issue is that the readings from a urine test need to be modified by a set factor in order to reach an equivalent blood alcohol level. This factor is known to be different depending on the individual. It can sometimes create readings that are too low or that are too high. Determining blood alcohol through urine testing is commonly accepted as being unreliable even by law enforcement officers.
One of the largest problems with urine testing to determine blood alcohol levels is that there could be serious time discrepancies because of basic biology. A urine test cannot tell whether a person is currently intoxicated. It cannot even provide any information about when a person was last drinking. All it can show is that there are certain compounds in the urine that are related to alcohol. These compounds could have been formed 24 hours before the test. The substance EtG can stay in the body for over three days. Additionally, it can take a few hours after drinking for any alcohol to reach the urine.
Tests Can Be Ruled Inadmissible In Courts
The reality is that urine testing for blood alcohol content can be ruled inadmissible by different courts. This is why it benefits drivers to choose a urine test over other methods if there is an option available. This lack of reliability has caused many people in law enforcement to stop administering urine tests when a DUI is suspected. This is especially true considering that the urine test is prone to the same types of lab errors, contamination and other problems that can affect blood tests. If you have been given a urine test, then there is a good chance that a DUI lawyer will be able to question the results in court.