Ignition Interlock Devices are not Breathalyzers

Ignition Interlock Devices which are in use in Massachusetts are often thought of and referred to as Breathalyzers. However, they’re really not. Although these devices measure a driver’s blood alcohol content, they’re not designed or certified to meet the accuracy standards which true Breathalyzers must satisfy. Ignition Interlock Devices were never intended to meet the stringent evidentiary standards which must be satisfied for admission as evidence in  Massachusetts Courts. Instead, the sole intended purpose of these devices is to lockout the ignition of someone who is under the influence of alcohol. Breathalyzers are subjected to extensive testing by the National Highway Traffic Safety Administration as well as private laboratories to ensure accuracy and reliability. This testing is based on standards established for scientific instruments. The Model Specifications for Breath Alcohol Ignition Interlock Devices are much different than those which Breathalyzers must pass.

I am aware of no court decision holding that ignition interlock devices are scientifically reliable enough to identify and accurately return a “positive” test indicating the presence of consumed alcohol in a person’s breath. Ignition Interlock related evidence is scientific in nature and a proper foundation must be laid for its introduction. Although Breathalyzer readings are commonly accepted in legal proceedings, based on prior court decisions, I am aware of no such decisions regarding the admissibility of scientific evidence generated by IIDs. Given the undisputed accuracy issues associated with ignition interlock devices, it is unlikely that their readings would pass muster and be admitted as evidence in court. IIDs are susceptible to false positive readings due to mouth alcohol, foods and other products containing alcohol, and influences of substances other than alcohol which the device misinterprets as alcohol. Also, evidentiary breath testing devices used in Massachusetts must have immediate calibration standard analysis performed. Ignition Interlock Devices do not perform this immediate analysis.

Lawyers representing clients who are facing 10 year license revocations for alleged ignition interlock violations in the form of initial start failures or rolling re-test violations should be aware that IID readings should not given the same weight as actual breathalyzer results and there are serious concerns regarding their admissibility based on Daubert-Lanigan admissibility requirements.