It's probably the flexible plastic cord that contained poisonous plastics. The Ipod earphone cords are poisonous too. my daughter uses hers all day long. i've told her it's poisonous, some nasty plastic i forget the name, that she shouldn't be handling it, rubbing it between her fingers etc. But I'd be a real big meany mom if I took it away from her.

we all grew up with those real poisonous soft plastics all around us Russ. they've just started labeling them the past few years. You probably have lots of other similar stuff in your house that simply wasn't labeled.

I probably just would have sprayed the mouse with a clear acrylic (which probably contains lead too). Lead is actually pretty common in plastics. And considering that so much of the plastics in the world are actually made in China these days that shouldn't be surprising.