Instant Lead Test Swabs are non-toxic and provide an instant, sensitive and specific test for leachable lead on painted wood, metal, vinyl, plastic, childrenâs toys, and dust. When lead is detected, Instant Lead Test Swabs begin to turn pink or red on contact, depending on the concentration of lead present. In most test situations results are developed in less than 30 seconds. Results may take longer to develop when detecting low levels of lead. Each kit contains test confirmation cards to verify individual test results.