Quote Originally Posted by BushMasterBoy View Post
Do NOT ever take a magnetron apart. They contain beryllium oxide. This stuff is almost as toxic as plutonium. The magnetron is not as tough as they say. If the output cavity is damaged, the whole thing goes to the landfill.

https://en.wikipedia.org/wiki/Beryllium_oxide
As long as you don't muck around with the ceramic, you're fine. I doubt the toxicity is as high as plutonium.