"Lead-based" refers to materials or products that contain lead, a heavy metal that can be toxic to humans and the environment. Common examples include lead-based paint, which was widely used in homes before being banned in many countries due to health risks, especially for children. Lead can also be found in plumbing pipes and some types of batteries. Exposure to lead can lead to serious health issues, including developmental delays in children and various health problems in adults. Because of these risks, regulations have been established to limit lead in consumer products and to ensure safe removal of lead-based materials in older buildings.