Sometimes a battery will pass harmlessly through the digestive tract. But if it gets stuck in the esophagus it reacts with saliva and begins to leak corrosive chemicals. These chemicals are similar to those found in drain cleaner. The chemicals from a stuck battery can burn a hole through flesh in as little as 2 hours. Untreated, they can cause death. According to the National Capital Poison Center, more than 3,500 people of all ages swallow button batteries every year in the U.S. More than 2,800 children annually end up in emergency rooms after swallowing lithium batteries. From 1991 to 2021, 66 children died from ingesting button batteries.