Physics

No, it’s not safe to put a LEGO minifigure (or any LEGO piece) in the microwave, and while it won’t explode, it’s a bad idea for a few reasons.

First, LEGO pieces are made of plastic (mostly ABS), and microwaving plastic causes it to melt and deform. You’d end up with a ruined, melted blob that’s completely useless. Not to mention, the melting plastic could release fumes that aren’t great to breathe.

Second, while the microwave works by heating water molecules, LEGO pieces don’t contain much water—so they won’t heat up evenly. The little bit of water they might absorb won’t cause an explosion, but it could create enough stress to crack the piece if it heats unevenly.

Finally, if your LEGO piece has any metal or electronic parts (like in some LEGO sets with lights or motors), that’s a huge no-no. Metal in the microwave can cause sparks, damage the microwave, or even start a fire.