In general, how long does it take before an alcohol level of 1.0 per mille (100 mg/100 ml) is cleared from the blood stream?

In German traffic rules, it is generally estimated that the body clears alcohol from the bloodstream at a rate of about 0.1 per mille (or 10 mg/100 ml) per hour. Since an alcohol level of 1.0 per mille corresponds to 100 mg/100 ml, it typically takes around 10 hours for this amount of alcohol to be fully metabolized and eliminated. This rule of thumb helps drivers understand how long they need to wait after drinking before it is safe and legal to drive again. The exact time can vary depending on individual factors like weight, age, and metabolism, but 10 hours is the standard general guideline used in Germany.