It isn’t hard having an alcohol-detecting device in your car. But you do need to be aware of it. Because an ignition interlock fuel cell looks for the molecular signature of alcohol, which is common to many substances, you’re liable to set it off accidentally.

When the device was installed you were probably advised to rinse your mouth to avoid a false positive from things like fruit juice and pizza dough, which can actually ferment in your mouth. But there are things in the air that can also make a difference to your breath test.

A lot of commercial products have alcohol, which is a very useful chemical. It preserves organic and other material; it stabilizes various mixtures; it won’t freeze; it provides moisture and then evaporates after a substance using it is applied.

An ignition interlock can detect that alcohol, though, so it’s possible you’ll blow a temporary fail if you’re used a product containing it.

Obvious examples:

• Hand sanitizer
• Hair spray
• Windshield washer fluid
• Antifreeze
• Cologne

All of these use a good amount of alcohol.

And is there a such thing as an air freshener fail? If you spray your car with it, that’s definitely something to watch out for. As for those little hanging trees, we’ve never seen one register on an interlock, but who knows? If you’re worried, keep the window open or stick it in the trunk until your interlock period is over. It’s a small price to pay for keeping your driving privileges.