Two things, many of those plates are collectible and there are people weeping to hear that you are throwing them away when they would give you money so they could put them in their display case.
The second thing is that it is not just lead that causes sparks but any metal.
So if there is any gold or silver in the pattern you will get sparks.
The plates are plain white with no pattern. I think that
people will eat off them if I send them to the thrift shop,
and I don’t want to poison anyone. I tested all the other
cups & stuff that I have and they didn’t shoot sparks.