The study found that after consumption of chocolates filled with alcohol and parapharmaceuticals containing alcohol, the alcohol was detected with the Alkometr A2.0 up to 4 minutes after consumption. When the Alco-Sensor IV breathalyzer was used, the measurement range (up to 2 mg/l) was exceeded only immediately after consumption of the two types of substances. After consumption of a standard alcohol-containing beer, the Alkometr A2.0 breathalyzer measured the presence of residual alcohol only in some cases. When three consecutive measurements of alcohol in the breath were performed at 15-minute intervals, the products tested did not influence the resulting measurements for alcohol. Forensic experts frequently are required to give an opinion about whether measurements of breath alcohol concentration were properly performed. If the time periods before or between readings have been too short, it is difficult to authenticate the reliability of the results. Attempts to explain positive results of measurement due to the consumption of foodstuffs, parapharmaceuticals, and diet supplements may come into play if breathalyzer measurements are not properly conducted. The results of the current study demonstrate the importance of waiting 15 minutes before or between measurements of breath alcohol in order to ensure that the measurements are not successfully challenged. 7 tables and 4 references