text: The validity of urine alcohol analysis in drunk drivers.
  Blood and breath are the specimens of choice for determining alcohol levels. A random urine specimen may not reflect a blood level because of the influences due to the stage of absorption, the quantity of urine in the bladder, and the frequency of urination. A urine sample may accurately reflect a blood level only 30 minutes after the bladder is completely emptied. Individual states that permit urinalysis for alcohol must provide procedures for sample collection and statutory limit levels.