There's a little-known risk to small children. Coin-sized lithium button batteries can cause severe injuries when swallowed.
In Australia, an estimated four children per week present to an emergency department with an injury related to a button battery.
The most serious cases involve 10 cent-sized batteries, but all sizes are hazardous. Batteries can get stuck in a child’s throat and burn through the oesophagus in as little as two hours. Repair can require feeding and breathing tubes and multiple surgeries.