Objective: The present study aimed to investigate if drinking one standard drink per hour could keep blood alcohol concentration below the legal limit of 0.05% in Thai men and women.
Material and Method: After overnight fast, 15 healthy Thai men and 15 healthy Thai women received 12 g of ethanol by drinking beer, rum, or carbonate mixed rum and their blood alcohol concentrations were monitored every 15 min for 1 hours.
Results: With one standard drink or 12 g of ethanol per hour, both Thai men and women had blood alcohol concentrations below 0.05%. At 45 min after drinking, women had significantly higher blood alcohol concentrations than men (p < 0.05). There was an inverse correlation between blood alcohol concentrations and the person’s body weight. Blood alcohol concentrations were very low when alcoholic beverage was taken immediately after a meal. However, drinking alcohol along with a snack had no effect on blood alcohol concentrations. Drinking carbonate mixed rum led to the highest blood alcohol levels, followed by beer either rapidly drinking or sipping and pure rum, respectively.
Conclusion: For Thai people, one standard drink per hour should be considered in the definition of safe level of drinking for men and women driving motor vehicles. It will be safer if drinking immediately after a big meal. Due to rapid absorption of alcohol in the bloodstream, drinking a beverage with low alcohol content could inebriate more rapidly.

Keyword: Blood alcohol concentrations, One standard drink, Thai