How to avoid IID false positives? Don’t eat or drink anything within 15 minutes of using an Ignition Interlock Device (IID). And since they come with “rolling re-tests,” don’t eat or drink while driving at all.
That’s the advice I give everyone about IIDs. It is shocking, and a life-change for many busy people who typically have coffee or food while driving. I give this advice, however, for a few different reasons:
(1) The IID does not measure alcohol. No breath testing machines do. Instead, what they measure — whether by fuel cell, or semiconductor, or infrared spectrometer — are methyl group chemical compounds. One of those compounds is ethyl alcohol. The machine assumes whatever it’s seeing is booze. People who work with gasoline or paint are at risk, so are people on any diet or who are fasting. In cross examination of Oregon State Crime Lab technicians, they have also admitted that false positives can be achieved through eating fresh bread or Altoids. In anecdotal use of various breath testing devices — on myself and colleagues — I have seen food and drink act as interferents and cause either (a) false positives or (b) vastly artificially high readings. Guess what the lock-out level is the the IIDs? It’s supposed to “Correlate well with established measures of alcohol impairment.” ORS 813.600(2)(c). So what are you thinking, .08? The AMA’s new recommendation for .05? Nope. .025% BAC.
(2) Any food or drink can cause a positive alcohol result. When you were arrested for DUII, your Oregon police officer used an infrared spectrometer — the Intoxilyzer 8000 — to gauge your BAC. Before doing so, science required him to “observe” you for at least 15 minutes to ensure you took nothing by mouth. Nothing. I suggest the same rule for use of an IID — take nothing by mouth for 15 minutes before use, and eat / drink nothing while driving.
(3) ADES is not necessarily on your side. ADES can use the downloaded “fails,” “lockouts,” and even any positive “alcohol” result to lodge Diversion Revocation proceedings. This is why camera-based IIDs are required by DMV rule. Point is, ADES in some counties considers itself part of the prosecution team and can aggressively pursue Diversion Revocation for people with IID problems. Cynics might say there’s a fiscal motivation — if you get kicked out of Diversion, you’ll be paying some new fees to ADES. Maybe you’ll be on probation the next 5 years, instead of Diversion for 1.
The legislature intended the use of IIDs prophylactically — and the studies support that use. In other words, IIDs vastly reduce the incidence of drunk driving. But as some ADES providers and prosecutors twist this new, prophylactic tool into a prosecution tool, abuses will follow. It is in the very nature of government, power, and surveillance — and let’s face it, that’s what IIDs are all about. Enforced government surveillance.
Finally, if you’re in the situation where ADES is trying to revoke your Diversion agreement for blowing booze into the IID, you’ll have some waiting to do. Your IID provider only downloads that information every 60 days or so, then you’ve got a time lag before ADES reviews your reports and decides to prosecute a revocation hearing or not. ADES is less likely to prosecute if it’s a single violation, or if you repeatedly blow into the machine and the BAC result rapidly dissipates (that’s a hallmark of using alcoholic mouthwash — also a Diversion violation, since you’re not allowed to use alcohol at all, but a more palatable Diversion violation). If, on the other hand, you repeatedly blow in the machine and it shows your BAC descending at about .02% per hour, that’s a hallmark of regular old drinking booze, and you’re likely to be prosecuted. In my experience, many IID violations are from “the night before.” Unfortunately, prosecutors, judges and ADES occasionally extrapolate back to recognize the very high BAC you drank to the night before to get to the .04% the morning after (usually in the mid .20% range). Drinking alcohol at all during Diversion violates your promise that you’d abstain — don’t drink, whether you’re done with treatment or not.
The safest way to avoid IID false positives is to simply not have anything to eat or drink for 15 minutes before using an IID. Don’t brush your teeth and use mouthwash immediately before getting in your car (and don’t use an alcoholic mouthwash at all). Don’t eat or drink while driving. Get through Diversion and get the government’s machine out of your car.