Study finds smart-app breath-testing devices to be unreliable

| Jun 2, 2021 | DUI

The penalties for drunk driving can be severe in Georgia and around the country, which is why many people who consume alcohol at restaurants or bars use portable breath-testing devices to make sure they are not intoxicated before getting behind the wheel. This would be a good thing if the devices functioned as advertised and provided accurate results, but the results of a study published in a leading scientific journal suggest that many of them do not.

All devices underestimated BACs

The researchers compared the blood alcohol concentration results from six popular breath-testing devices with the results from blood tests and the Intoxilyzer 240 machine used by police departments. All of the devices underestimated BAC levels, and two of them failed to detect BACs that would lead to a DUI charge half of the time. One of the reasons for this lack of accuracy is the way the devices work. Only about 10% of ingested alcohol is released in breath and urine. Breath-testing devices measure this 10% and then use that figure to determine blood alcohol levels.

Police machines also unreliable

This is why even the sophisticated breath-testing equipment used by law enforcement can be inaccurate. Police departments in Georgia use the Intoxilyzer 8000, which is considered one of the most reliable units available. When toxicology experts tested the Intoxilyzer 8000 in 2005, they said the device provided inaccurate results in virtually every test. Courts have invalidated more than 30,000 breath tests conducted by police officers in New Jersey and Massachusetts, and a judge in Pennsylvania said that he did not think any of the breath tests used as evidence in drunk driving cases could withstand close scrutiny.

Challenging toxicology evidence

Experienced criminal defense attorneys could seek to have breath-test results excluded when the equipment used by the police was not properly calibrated or maintained, and they could also question this type of evidence if their clients follow diets low in carbohydrates or suffer from medical conditions like gastroesophageal reflux disease, asthma or diabetes. This is because ketogenic diets create chemical compounds in the body that mimic alcohol, rescue inhalers contain alcohol, and acetone levels in diabetics are sometimes thousands of times higher than normal.