Drinking and driving “safely”: Who uses a breathalyzer and when?

Breathalyzers are often promoted on the grounds of safety. However, drivers who use them to avoid illegal blood-alcohol levels inadvertently expose themselves to sleepiness-related risks following alcohol intake. Personal breathalyzers may even be counterproductive if they make more drivers engage in more frequent or habitual drinking and driving. This study explores the extent to which and how drivers use the breathalyzer. We contacted nine major breathalyzer importers in Finland and found out that the estimated number of devices delivered during 2006 was almost 50,000, equaling approximately one percent of population and one-and-a-half percent of driving-license holders. Survey data on a representative sample of Finnish active drivers (N = 1121) showed that 11.5% owned a breathalyzer. More men than women own and use a breathalyzer, and most often the men are aged 36–55 years. These men also use it more often after acute drinking (32% vs. 20% in the whole sample). Seventy-nine percent of breathalyzer use occurs the following day after evening or night drinking. Therefore, while in a smaller percentage of cases the risk involves the additive and interactive effects of alcohol and sleepiness in the evening, most users expose themselves to risks related to daytime sleepiness due to drinking the previous night.