Testing Precautions for Circuit Board Testing: In tests performed in our laboratory LeadCheck® Swabs have never failed to detect lead on circuitboards, leads, or other small soldered connections. Click this link for examples of items tested. Test surfaces must be clean and free of any material (mold release agents, flux, or oils) that might prevent the LeadCheck® Reagent from coming in direct contact with the surface. Alcohol pads are provided in the LeadCheck® Circuitboard test to prepare surfaces prior to testing. Commercially available board cleaners can also be used to remove surface contaminants. In rare cases scratching or abrasion may be required. When performing the Direct Testing Method, gray deposits may appear on the Swab tip if surfaces are not properly prepared. The LeadCheck® Reagent reacts to lead in solder or metals very quickly. When lead is present the tip of the Swab should turn pink immediately – before gray deposits appear. After testing residual LeadCheck® Reagent may be removed by rinsing the part with water or a board cleaner.