20 X 2016 CR2016 2016 3V Lithium Button Cell Coin Battery DL2016 LM2016 New. 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.
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