Ohio has two drunk driving laws found in ORC Sects 4511.19A(1)a and 4511.19A(1) b-i.
under 4511.19A(1)a, it is a 1st degree misdemeanor to drive under the influence of alcohol and/or drugs.
Under 4511.19A(1)b, It is a 1st degree misdemeanor to drive with .08% or more of alcohol in your blood. Sections A(1)c -i deal with various other methods of measuring alcohol in the blood without reference to the effect of that alcohol on your ability to drive.
If the operator of the vehicle is under the age of 21, a conviction will result from a blood alcohol level of .002 or above. If the reading is .002 or above but less than .08, the conviction is a fourth degree misdemeanor for a first offense. There is no need for the police officer to prove that there was any impairment.
Note: In most cases, a driver will be charged with having a blood alcohol level above the legal limit and also with driving impaired. Both offenses will be charged even though there is only one act. The driver can only be convicted and punished for one. (The punishments are identical for both offenses.)
Under ORC section 4511.19(G)1(d) the offender may be charged with a felony if he or she has been convicted of three or four OVI s in the past 6 years or 5 OVI s in the past 20 years. Yes-The Judge looks at your driving record from 20 years ago!