If your child swallows a button cell battery, you have an emergency on your hands. Alert the emergency services immediately by dialling the code in your area. Do not induce vomiting under any circumstances, medical professionals say. Contact with the moist mucous membranes in the oesophagus results in a permanent current flow between the negative and positive poles of the battery, leading to the formation of hydroxide ions, which increase the pH value. That can lead to burns to the oesophagus, c