Eating a plate is a bad idea. You should not eat any plate.

If a plate breaks, or chips, you should not eat any of the fragments of the plate, the food that was on the plate when it broke, or continue using the plate. You should clean it up, put the fragments in a sealed plastic bag, and put it in an outdoor trash can as soon as you can.

My guess is that a Corelle plate is more likely to meet US standards for plate safety at time of manufacture than any brand of imported plates. My guess is that even a pre-2005 Correlle plate is less likely to be problematic than an inexpensive plate manufactured and imported in the last 6 months.

If you are concerned about lead in your dishes, buy new, high quality, Ameican made dishes, make sure to inspect your dishes before use and stop using anything that has a chip, a crack, or that the glazing has any change in appearance, and make sure the plate has no metallic looking decorations. Do not buy or use cheap plates, or expensive, decorative plates.

If you do break a plate, do not eat the food that was on the plate, or near the plate when it broke. If you can ventilate the area, do so. (Turn on an exhaust fan, open a window.) If you happen to have an N-95 mask handy, go ahead and wear it while you are cleaning up the mess. Use a wet paper towel to pick up the plate pieces, and another one to wipe down the area where the plate was. Put the plate fragments, any nearby food, and the paper towels that you used to clean up in a plastic bag, seal it, and take it out to an outdoor trash can as soon as you finish up cleaning. Wash your hands with soap and water, and be sure to scrub thoroughly, including under your nails. Have people avoid the area where the plate was broken until the air has had a chance to be vented.

Now, my bet is someone is going to say that this cleanup plan is unrealistic and silly, and is overkill. They will have a point, but... the question is understanding the risk and deciding what is right for you. And that is the entire point of the question, now isn’t it?

I’m going to keep eating off of vintage Corelle, and even more stupidly, cheap imported third world country plates. Been doing it for decades. That is a small risk, since I live in a pre-70’s house, on a pre-70’s street, near industrial areas, in a region where coal is used to generate electricity. But yeah, I am going to wipe down the area where that plate breaks and take out the trash and wash my hands, and open a window.