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Can food and pollution affect breath test results?

On Behalf of | Oct 4, 2019 | DUI/DWI/OUI

When law enforcement officers suspect that a driver is operating a vehicle under the influence of alcohol, they may use a breath test device to measure the driver’s blood alcohol content level. If you have ever been pulled over on suspicion of a DUI, you may have been asked to submit to one of these tests by exhaling into a breath test device. Research performed by the State University of New York at Potsdam found, however, that the results from these devices may be inaccurate. 

Researchers discovered that in addition to measuring the amount of ethanol alcohol present in the exhaled breath sample, the devices measure other substances that have a similar methyl group structure. These may include the following:

  • Residual food in the mouth, such a certain bread starches

  • Residual liquid, blood or vomit in the mouth

  • Dirt, tobacco smoke and pollution found in the air

  • Fumes, such as gasoline, cleaners or paint

In addition, the device may give inaccurate results if the machine is not calibrated correctly to work in the relative temperature and humidity of the air. The law enforcement officer must use the breath test analyzer correctly in order for it to work correctly. 

The blood alcohol content level results obtained from a breath test device can differ from those obtained from an actual blood test by as much as 15%. Furthermore, one in every four people who are tested using the breath test device may have exaggerated results, which could lead to a wrongful DUI. 

This information is intended to educate and should not be taken as legal advice.



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