Top 5 Causes of False Positives While Using Ignition Interlock

by Vincent Ieda on February 12, 2013

A driving under the influence (DUI) conviction usually leads to several negative repercussions. These consequences can include high fines, community service and even jail time. One penalty that many people are finding it difficult to live with is the installation of an ignition interlock system on their vehicle. Interlock technology is meant to prevent drunk driving, but in actuality, there are several things that can cause false positives on these devices.

1. Mouthwash

Most people who have to get ignition interlock devices are instructed to rinse their mouth with water after using mouthwash. This is because certain types of mouthwash can be up to 30 percent alcohol by volume, which is only five percent less than drinks like Jagermeister.

Simply washing your mouth with water and waiting fifteen minutes will allow an ignition interlock device to perform an accurate test. This is very important considering the fact that even Monitech INC Charlotte NC brand devices, arguably considered the most trusted on the market, can mistake rinsing with mouthwash with consumption of alcohol.

2. Certain Diets

Many individuals find out the hard way that certain diets or even being diabetic can cause a breathalyzer to return a false result. This is true for many ignition interlock devices as well. This occurs because diabetics and dieters have exceptionally high levels of acetone in their bodies. This acetone is misread as alcohol, which can cause someone to easily fail their test.

3. Spicy Foods

Unfortunately, for those who like a little zest in their life, eating spicy foods can actually cause a false positive on an ignition interlock device. This can be especially annoying for someone trying to drive home after having one too many enchiladas at the local Mexican restaurant.

Unfortunately, some spicy foods can mix with the hydrochloric acid (HCl) in an individual’s stomach and create a gas known as methane. Much like the aforementioned plight of dieters and diabetics, this heightened level of methane can lead to a false positive. It’s sad to think that a person could end up back in jail just because they had a bit too much salsa.

4. Chloraseptic 

Certain analgesics like Chloraseptic spray, much like mouthwash, contain alcohol. The alcohol in these products isn’t enough to cause intoxication when taken properly, but it is enough to cause a false positive on ignition interlock devices.

Monitech systems are advertised to police agencies as devices that don’t cause false positives. Unfortunately, this may only be part of the truth. Returning a positive result for Chloraseptic sprays may be accurate in the sense that it is reading alcohol, but when it comes to legal intoxication, it is far off.

5. Cinnamon Rolls or Donuts 

Surprisingly enough, both donuts and cinnamon rolls can sometimes result in false positives. This is due strictly to the fact that these foods contain yeast and sugar, and these two ingredients are used to produce alcohol. Subsequent tests will likely show that the initial one was inaccurate, and rinsing your mouth with water can help prevent this misread.

A person who fails a rolling test due to these sweet treats, or any reason for that matter, should refrain from immediately stopping and simply wait for the upcoming retest. These retests will usually show that the initial test was inaccurate and serve as great evidence if the issue leads to court.

A false positive on an ignition interlock device can be extremely detrimental for a person who has already racked up a DUI conviction. Anyone who experiences one of these false results needs to immediately note exactly what they were doing both before and during the test. If someone fails a rolling test, it’s not a bad idea to stop at a police station and ask for a breathalyzer test to show that the interlock device was inaccurate. Overall, it’s usually necessary to find an attorney to prevent serious consequences from these false positives.

Ieda Vincent is a science educator and is very familiar with tests displaying false results and what it takes to methodically establish a resolution.  Powers McCartan, PLLC have a real interest in the inaccuracies of the Monitech INC Charlotte NC system. They have many years experience training and educating other lawyers on the mechanics of interlock ignitions.

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