The element often used in batteries and is considered toxic is lead. Lead is a heavy metal that has been widely used in the production of lead-acid batteries, commonly found in vehicles and backup power systems. While lead is effective for energy storage, it poses significant health risks if ingested or inhaled, leading to lead poisoning. Symptoms of poisoning can include developmental issues in children, neurological problems, and various health complications in adults. Due to its toxicity, there is an increasing emphasis on recycling and safely disposing of lead-containing batteries to minimize environmental and health hazards.