When it comes to DUI/OVI tests in Ohio, a urine test is the least reliable of the three chemical tests that a law enforcement officer has to choose from. Under current law in Ohio, urine tests can be admissible in evidence in DUI/OVI cases.
Urine tests are the least favored choice in Ohio because they do not measure the actual blood alcohol concentration in your system. They only measure the remnants, and they are not precise. Controlled substances can remain in your system for extended periods.
Marijuana, in particular, can be detected in your system for nearly a month in certain cases.