CHEMetrics Inc., of Calverton, Va., announces its Vacu-vials Test Kit (K-4003) for the measurement of fluoride in water. Fluoride can occur naturally in water, and may also be added in controlled amounts. Accurate determination of fluoride concentrations has become increasingly important as the practice of fluoridation of drinking water supplies as a public health measure has increased. Monitoring and maintaining optimum fluoride levels are essential to sustain effectiveness and safety of the fluoridation process.