Section 634.34 - Blood alcohol concentration standards(a) Administrative revocation of driving privileges and other enforcement measures will be applied uniformly to offenders driving under the influence of alcohol or drugs. When a person is tested under the implied consent provisions of § 634.8 , the results of the test will be evaluated as follows: (1) If the percentage of alcohol in the person's blood is less than 0.05 percent, presume the person is not under the influence of alcohol.(2) If the percentage is 0.05 but less than 0.08, presume the person may be impaired. This standard may be considered with other competent evidence in determining whether the person was under the influence of alcohol.(3) If the percentage is 0.08 or more, or if tests reflect the presence of illegal drugs, the person was driving while intoxicated.(b) Percentages in paragraph (a) of this section are percent of weight by volume of alcohol in the blood based on grams of alcohol per 100 milliliters of blood. These presumptions will be considered with other evidence in determining intoxication.