Last Updated: 05.04.2020

Evidentiary Breath Testing (EBT for short) is a very technical process.  As explained in our prior article found in our Maryland Lawyer Articles, there are a number of issues that can occur with the breath testing process.  These issues can influence the breath test accuracy and its admissibility as evidence in a Maryland Court.  Just a few of the problems regularly occurring in breath testing include failure of law enforcement to procedurally comply with regulations, environmental contamination, and occasionally even localized Radio Frequency interference can skew results.

Mouth alcohol in DUI Breath Testing cases

One major issue that regularly occurs but is seldom identified as a defense is that of “mouth alcohol.”  Mouth Alcohol occurs when undetected, raw, unabsorbed alcohol in the mouth, throat, and/or stomach can falsely elevate the results of your breath test.  This occurs in one of two ways:

  1. Alcohol is ingested immediately prior to the administration of the EBT (i.e. taking a swig from your Jack Daniel’s bottle right before you give the EBT)
  2. Alcohol is regurgitated or eructated (burped) from the stomach or GI tract

The issue of Mouth Alcohol is widely recognized in the scientific community, as evidenced by the legitimate research that has been conducted into establishing proper procedures to safeguard against false-positive results.  See e.g. here. Through this research, legislatures and researchers developed steps law enforcement should take to reduce the likelihood of false-positive results in DUI cases.

Based upon these scientific findings, here is what police should do for EVERY violation of Maryland DUI laws breath test:

  • Observe the person for 20 minutes prior to giving the breath test sample to be sure the mouth alcohol is cleared from your airway
  • Be sure you don’t regurgitate any substances
  • manufacturers have installed “mouth alcohol” detectors to make sure you have a sufficient breath result (which the EC/IR machines in Maryland have)
  • Inspect your mouth for foreign substances (i.e. gum) prior to the breath test
  • Use a new (clean) mouthpiece for every breath test
  • Obtain multiple breath samples for each person

As a Maryland lawyer who regularly defends people against violations of Maryland DUI laws, we see that these protocols are not always followed.  Failure to follow these protocols can result in, not only, increased breath test results, but additional administrative sanctions and criminal convictions.  If you find yourself charged with a violation of Maryland DUI laws, be sure to contact your favorite Maryland Lawyer at ENlawyers.