Did you ever wonder about those little sticky tabs on your hearing aid batteries? They aren’t there just to identify the battery size. The most common hearing aid batteries are called “zinc air” batteries because they are air-activated. A manufacturer’s sticker ensures they remain inactive until the sticker is removed. Once peeled off the back of the battery, oxygen in the air interacts with the zinc in the battery to “turn it on.” The battery can not be deactivated by replacing the seal, so once it is removed the battery will remain in an active state until the power is drained. Zinc-air cells contain no toxic compounds and are neither highly reactive nor flammable. For more detailed information, check out these three web sites:
http://www.healthyhearing.com/help/hearing-aids/batteries
http://deafness.about.com/cs/haidbatteries/a/batteries.htm
https://pubs.rsc.org/en/content/articlelanding/2014/cs/c4cs00015c