In Massachusetts a police officer or state trooper administering an OUI breath test “shall observe the arrestee for no less than 15 minutes immediately prior to the administration of the breath test” according to 501 CMR 2.13.
As stated by the Appeals Court,
The purpose of the waiting period under surveillance is to make sure any contaminants (e.g., tobacco smoke) in the test subject’s mouth that might affect results have cleared and to be sure that the test subject is not burping or hiccoughing.
Commonwealth v. Kelley, 39 Mass. App. Ct. 448, 452, note 5
Should the breath test operator fail to properly observe the arrestee for the required amount of time, the test may be deemed unreliable and inadmissible at trial.
Additionally, if the arrestee burps, hiccoughs, sneezes, puts his hands to his mouth, or does anything else that might skew the test reading, the 15-minute observation period must start over. Failure to restart the observation period may again result in an inadmissible test result.
Breath tests that fail to comply with the observation requirement can be challenged through a “Pierre motion” based on the Appeals Court decision in Commonwealth v. Pierre, 72 Mass. App. Ct. 230 (2008).