The LeadAlert chemical spot test kit utilizes rhodizinate as the indicator for the presence of lead. Use LeadAlert in the field for screening/rapid testing. Indicating solutions give accurate positive/negative results in less than a minute with sensitivity to 0.5 micrograms. When lead is present and solubilized by the leaching solution (a mild, organic acid), a red or pink color will be seen on the tip of the collection swab or test card. Each kit comes contains everything needed for 40 qualitative tests, including coring tool and brush.