Lead paint testers are designed to check whether there is an unsafe level of lead in the paint which has been used inside or outside a house. There are two types of lead paint tester which are available. The first is a DIY kit which uses a drop of sodium sulfide to test for the presence of lead in a paint chip. The solution turns darker if the paint contains lead. This test may produce false positive results if other resins are present in the paint, and may also be difficult to evaluate on dark-colored paint. The second type of lead paint tester is carried out by a professional, who uses X-ray fluorescence to check for lead. Alternatively, a sample may be sent to a laboratory which will quantify the amount of lead in the sample and determine whether this may be a dangerous level.