4 hours needed to drive after drinking

“Three hours have passed since I drank, but I’m still wondering whether it’s okay for me to drive...”

Korean drivers often ask this question to themselves around this time of the year, the peak season for year-end gatherings and parties after work. They are better off leaving their cars behind and using public transportation or a proxy driver service.

More than a few people, however, still choose to drive. An official police blog, polinlove.tistory.com, recently released a method of determining blood alcohol concentration, namely the Widmark formula.

Named after the Swedish physician E.M.P. Widmark, who invented it, the formula works like this. Take the amount of drinks consumed and divide it by weight. Then apply the gender constant, or the difference in alcohol absorption between men and women, to get the result. The formula is used by police to get the blood alcohol concentration of hit-and-run drivers or those who refuse to take a breathalyzer test, or when the driver’s blood alcohol concentration needs to be determined a few hours after a car accident.

Based on the formula, an average of four hours and six minutes is needed for a 70 kilogram man to break down a 360-millimeter bottle of soju (traditional Korean liquor) at 19 percent alcohol, meaning he should wait at least four hours after drinking a bottle of soju to avoid being caught for driving under the influence. It takes about four hours and 47 minutes for a 60-kilogram man and three hours and 34 minutes for an 80-kilogram man to break down a bottle of soju, meaning lighter people need more time to decompose alcohol in the body.

Women need more time than men, with a 60-kilogram woman needing an average of six hours for a bottle of soju, or 1.5 hours longer.

The type of drinks also affects the result. A 70-kilogram man needs five hours and 22 minutes to break down a beer of 2,000 cubic centimeters at 4.5 percent alcohol, two hours and 41 minutes for a bottle of makgeolli (traditional Korean rice wine), six hours and 28 minutes for four glasses of liquor, and five hours and 50 minutes for a bottle of wine.

A police source said, “The time needed to break down alcohol differs from person to person, so using the Widmark formula to determine whether to drive or not can be dangerous. Regardless of the theory, if a driver is found to have a higher blood alcohol concentration, he or she will face prosecution.”

neo@donga.com