Can you put polystyrene in the microwave oven I want to know for sure if you can use polystyrene trays (such as those that meat comes in) in the microwave oven?

I have read some fairly official looking reports and articles that say there's not danger, but there is some anecdotal evidence that they can melt, which while apparently harmless, is not ideal.
Well, I can tell you with absolute authority that polystyrene melts in the microwave.

Here's a chunk of polystyrene cut from a foam shipping container. I double checked with the website (Propak), and the stuff is polystyrene.



I placed a random chunk of chicken on the cube, and microwaved on high for 1 minute.

 

So yeah, it melts. Is it toxic if it melts into your food a few times? Probably not. Should you do it? Probably not.