The term "mouth alcohol" refers to the presence alcohol in the mouth. A breath test result will show higher than normal results if the suspect has mouth alcohol. The breathalyzer uses a complex formula that takes the amount of alcohol and multiplies it by 2100 to get its results. The machine assumes the breath starts from the lungs. Factors such as these can create discrepancies is test results.
There are other potential reasons for having mouth alcohol:
Breath fresheners do have trace amounts of alcohol. Products such as Listerine and Binaca contain small levels of alcohol and can certainly affect breath test results. Cough medicines such as NyQuil also contain alcohol and can affect test results the same way.
Bodily functions such as hiccups, burps, or even vomit can also affect the test results. Actions such as these bring the vapors of alcohol from the stomach back up to the mouth.
A hiatal hernia can also cause elevated test results.
Dental caps and bridges can capture alcohol in a crevice and be blown out by a breath.
If the suspect has a chronic reflux condition, alcohol can travel up from gastric distress.