Yes, it is suitable for the microwave. You can see that very faintly on one of them. I have just bought 2 pieces to test. It is labelled on the packaging that it is microwave-safe.
Hello, I'd have to check the manufacturer's website but it's not written on the back of the box. But it's great for storage space. I've got all 3 box sizes and they really don't take up any space. The lids are also good because the seal is built into the lid and is not removable.