The police employ alcohol breath tests to check how much our blood alcohol concentration is. It utilizes the total amount of alcohol in our exhaled breaths to accurately estimate the amount of alcohol in our blood, and it is also known as blood alcohol concentration (BAC). How long alcohol stays in our breath depends on many factors, including the person’s age, weight, gender, how much alcohol they have consumed, and when they last ate food. Breathalyzers can give false-positive test results, especially after using Listerine mouthwash which contains a high amount of alcohol. Therefore it is not recommended to do a test for 15 minutes after eating or drinking something. On average, it can be detected up to 24 hours after the last drink you have had.