Observation Period


The observation period is critical to getting a valid blow on the breath test. It is also frequently overlooked by police officers. Prior to the breath test, an officer is required to conduct a 15-min observation/deprivation period.

This time is necessary for any potential mouth alcohol to evaporate. At the beginning of the observation period the officer should physically look in your mouth to ensure that you have nothing in there: no chewing gum, chewing tobacco, dip, hard candies, or anything else. However, since police couldn’t be bothered to actually look, the state amended the regulation to simply require that they ask if you have anything in your mouth.

19 CSR 25-30.060 establishes operational procedures for each of the approved breath machines. The observational period is step two on each checklist. It is that important.

The driver may not smoke or ingest any food or fluids during the observation time period.  If vomiting occurs, the observation period must start over. The officer has to ensure that you complied with this deprivation period.

If you have any concerns about the observation/deprivation period, you need to bring those to your attorney as soon as possible. There may be video he or she needs to order the police to preserve.