WHAT IS THE SODIUM SULFIDE METHOD OF SCREENING FOR LEAD PAINT?
The sodium Sulfide method requires an inspector to break through and expose all the layers of paint on a surface; this is done by scoring (cutting through the surface) in a v-shape. He/She then applies a sodium sulfide solution to the newly exposed surfaces. A grey to black coloration will appear on the paint layers containing lead. This method is not foolproof, however, and is subject to chemical or visual interference. For example, cadmium can give false positive reaction; this chemical is commonly used as a pigment in paints. Varnish also can give a grayish or black appearance. WHAT IS THE X-RAY FLUORESCENCE (XRF) METHOD OF SCREENING FOR LEAD PAINT? The X-ray fluorescence method is the most widely accepted screening method. An inspector uses a special instrument to take readings of x-rays emitted from the lead in the surface. The instrument’s radioactive source excites the lead in the paint to emit x-ray radiation at a certain frequency. The detector portion of the instrument then m
