More Issues with DWI Urine Testing: Fermentation

Posted On March 31, 2010 by Charles Ramsay

We have previously blogged about the unscientific nature of Minnesota's urine testing regimen. Despite some adverse court decisions, we continue to find ways to demonstrate our clients' innocence. Here is the story of one case where we revealed this month another reason why urine testing should not be used in DWI cases.

My client ("James|) was arrested for DWI and given a urine test. The result was .16. James, a former peace officer, was adamant the result was wrong. During my initial interview, I learned that the container into which James deposited his urine sample was empty before he filled it.

I explained to James that Minnesota's DWI urine kits are to include a white powder -- 1 gm of Sodium Fluoride. The purpose of the chemical is to prevent any sugars present in the urine from being converted to ethanol in-vitro after sampling by fermentation. Fermentation is likely to occur without the powder, particularly when the sample goes unrefrigerated.

One way to determine whether fermentation occurred is to retest the sample by an independent lab. Fermentation is likely if the independent test reveals a higher alcohol concentration than the state's initial test result. James paid to have the sample retested. The result: .18

The urine alcohol concentration had increased by 12 ½ percent!

We retained the services of a reputable forensic scientist for his opinion. After reviewing the police and toxicology reports he concluded:

1. The urine alcohol level is clearly rising in this sample going from a .16 to a .18 on retest.

2. Fermentation is the cause of this alcohol increase.

3. Fermentation proceeds at room temperature and this sample spends 4+ days at ambient temperature before it is refrigerated at [the Bureau of Criminal Apprehension (BCA)]. It spends unknown, but likely several days, at room temperature during BCA analysis in which it is goes up in alcohol level.

4. The client reports no powder in the kit which would significantly accelerate fermentation.

5. The BCA did not test for glucose or preservative in defendant's sample.

The clear interpretation of the data is a rising alcohol level. That makes this test and the sample unreliable to show the actual level of defendant's urine at the time the sample was collected.

The Urine alcohol level is not related to intoxication so the sample is of no value to the issue of intoxication.

My client was right!

This demonstrates that urine testing continues to be an unreliable method of determining the alcohol concentration of a person arrested and charged with DWI. If you have been arrested, call the Ramsay Law Firm immediately.