0.08 Percent FindLaw Newsletters Stay up-to-date with how the law affects your life Iowa DUI (OWI) Laws: Blood Alcohol Concentration (BAC) Limits and Implied Consent “Per Se” BAC Limit 0.08 Percent Zero Tolerance (Underage) BAC Limit 0.02 Percent Enhanced Penalty (Aggravated) BAC Limit 0.15 Percent 7 more rows • Mar 12, 2018