I'm probably over reacting but was shocked by what I just heard on the radio. Those tiny batteries in all sorts of toys and other things are a serious hazard if swallowed. Apparently they can get stuck and cause caustic soda burns to a child's windpipe or food pipe. If your child does swallow one the advice is to go straight to Accident and Emergency, immediately. Some toddlers have even died.
This seems to to be so horrible and dangerous but did you know? I certainly didn't. Needs to be better known IMHO.