Lead paint or lead-based paint is paint containing lead. As pigment, lead(II) chromate (Pb Cr O4, "chrome yellow"), Lead(II,IV) oxide, (Pb3 O4, "red lead"), and lead(II) carbonate (Pb C O3, "white lead") are the most common forms. Lead is added to paint to accelerate drying, increase durability, maintain a fresh appearance, and resist moisture that causes corrosion. It is one of the main health and environmental hazards associated with paint. In some countries, lead continues to be added to paint intended for domestic use, whereas countries such as the U. S. and the UK have regulations prohibiting this, although lead paint may still be found in older properties painted prior to the introduction of such regulations. Although lead has been banned from household paints in the United States since 1978, paint used in road markings may still contain it. Alternatives such as water-based, lead-free traffic paint are readily available, and many states and federal agencies have changed their purchasing contracts to buy these instead.