Well there is a recycle number on your plastic kettle, that tells you what kind of plastic it is.

I don't own a electic kettle, just a stainless kettle that goes on top of a stove. I don't think the plastic in a kettle is a real issue. Just never bought a electric one.

The plastic of bottled water seem to give a taste in the water when exposed to longer periodes of heat, but the is pretty long exposure compared to a reusable bottle or waterkettle.