Quarternary Test Paper (QT 40)(15 FT ROLL). Hydrion QT-40 Quaternary Test Paper provides a simple, reliable, and economical means to measure the concentration of Quaternary Sanitizers, particularly muli-quat broad range quaternary ammonium sanitizer solutions. With color matches at 0-150-200-400-500ppm (parts per million), the test paper measures concentrations between 0-500ppm, detecting exhaustion of solutions that should be replaced as well as helping to avoid using excessive amounts of sanitizing agents. Federal, State and Local health regulations require users of Quaternary Ammonium Sanitizer Solutions to have appropriate test kits available to verify the strength of sanitizer solutions. Sanitizer solutions are essential in the food service industry to ensure that sanitizers are at the proper concentration specified by the individual manufacturer.