Button/coin batteries are hazardous and should be kept away from children (whether the battery is new or used).

Never allow children to handle button batteries.

If a non-lithium button/coin battery (e.g. alkaline, silver oxide) is swallowed or placed inside any part of the body, the battery can cause serious injuries.

If a lithium button/coin battery is swallowed or placed inside the body, the battery can cause severe or fatal injuries in 2 hours or less.

Seek medical attention immediately, such as on 13 11 26, even if you only suspect that a button/coin battery might have been swallowed or placed inside any part of the body.