The most reliable measurement of blood alcohol content (BAC) obtained by direct analysis is a blood test. However, for reasons of convenience, BAC is sometimes obtained through indirect analysis. The purpose of an indirect analysis for BAC is to obtain an estimate of the coexisting BAC. The most common way to obtain a measure of the coexisting BAC is to obtain a breath-alcohol analysis. However, urine analysis may be used to obtain the coexisting BAC.
The basis for examining a urine sample to obtain the BAC involves understanding some scientific concepts. When alcohol is absorbed into the blood, it is distributed to all of the watery fluids of the body. After it is fully distributed, the percentage of alcohol in each body fluid bears a set relationship to the water content of that fluid. At equilibrium, alcohol is uniformly distributed throughout the water in the body. This distribution allows for an estimate to be made of the alcohol content of one fluid (e.g. blood) if the alcohol content of another fluid (e.g. urine, saliva or blood serum) and the relative water contents of the two fluids are known.
In some jurisdictions, urine-alcohol analysis is an acceptable alternative to blood-alcohol analysis. In those jurisdictions, the results of urine testing may be used as evidence in a DWI trial to show whether an individual has or has not recently ingested alcohol. Results of the urine-alcohol analysis can be reported directly as a urine-alcohol concentration or converted into an assumed “equivalent” BAC. Both saliva and perspiration have been used in this way also.
Urine-alcohol analysis is an acceptable alternative to a direct determination of BAC in a number of states. In New York, under the New York Vehicle & Traffic Law section 1194(2)(a), a driver gives their implied consent to chemical testing if they are subject to a traffic stop on suspicion of DWI. This statute specifically authorizes urine alcohol measurements under its implied consent provision. In some states that have DWI statutes worded in terms of BAC, a urine-alcohol concentration (UAC) is converted to a BAC by use of a simple ratio. In other jurisdictions, DWI may be proved by evidence of a certain number of grams of alcohol in a designated quantity of urine.
There is considerable disagreement in the scientific community about the accuracy and relevance of UAC test results in determining BAC or intoxication. Unlike blood testing or breath testing, there is little evidence of studies that can accurately show a correlation between urine-alcohol test results and alcohol impairment.
The attorneys at the law firm of Nave DWI Defense Attorneys are experienced in handling DWI cases. If you need a lawyer who can help you obtain the best possible outcome in your DWI case, call the law firm of Nave DWI Defense Attorneys at: (877) 435-7394
The exclusive purpose of this article is educational and it is not intended as either legal advice or a general solution to any specific legal problem. Corporate offices for Nave DWI Defense Attorneys are located at 269 W. Jefferson St.; Syracuse, New York 13202; Telephone No.: (315) 473-0899. Prior results do not guarantee a similar outcome. Attorney Advertising.