Adulteration of urine samples may cause erroneous results when drug testing by either interference or by destroying the drug evidence in the urine. Dilution of urine with water is probably the most common adulteration method. Bleach, vinegar, Visine, sodium bicarbonate, sodium nitrite, Drano, soft drinks and hydrogen peroxide are examples of compounds used to adulterate a urine sample. It is vital to ensure the integrity of a urine sample in every drug test.