LR54, 189-1, RW89, L1131, V10GA, GP89A, LR1130, 189, 389A, AG10, D189. Button batteries react with saliva to create caustic soda, which is the chemical often used to unblock drains. If a child swallows a button battery and it gets stuck in their food pipe (oesophagus), it can burn a hole and cause internal bleeding, or even death.