Rapid Blue Dissolve Bluing Tablets are placed directly in the toilet bowl or water tank. Bluing tabs will dye the water blue, which will negate any donor from using clear toilet water to dilute their urine samples or detect water leaks in any plumbing application. If a donor attempts to dilute their own specimen or substitute the entire specimen with the water from either of these sources, the collector will be able to easily detect it. *REQUIRED PER FEDERAL REGULATIONS In a federally-regulated urine specimen collection, blue dye is required in the toilet bowl and tank when utilizing a standard toilet per Section 7(2) of the DOT Urine Specimen Collection Guidelines promulgated by the Office of Drug and Alcohol Policy Compliance.