Just Bento

Sometimes they say not to microwave with the lid on. I have microwaved my daiso dragonfly box (without the lid and for a very short period of time) and it didn't do any harm. Not that I'm advocating it, just saying. :)

I own 3 different bento boxes and I have microwaved all three (without the lids) and everything was perfectly fine.

Most plastic bento boxes made these days can be microwaved, without the lid on - the lid usually has some type of silicon or similar sealing element to it, which may get damaged in the microwave. You should not microwave stainless steel or other metal boxes, obviously, or wooden ones. Melamine is probably best not nuked.

Hubby learned the hard way - a couple of weeks ago he put his inexpensive Daiso bento box into the microwave with the sides clips in place. The container was fine, but the lid cracked and the frame warped. He won't be making that mistake again.

I've found some good microwave/dishwasher safe boxes on Bento & Co.

I've just got an aladdin bento box (my first) from firebox.com and it actually recommends microwaving for best results (but without the lid). I've yet to try it but it looks very well made

I've just bought an Aladdin bento box from Firebox.com and it actually recommends microwaving (without the lids). My first bento box so I've yet to try it out but it looks well made (if a bit of an odd shape - two stackable and insulated cylinders).

I believe that my inexpensive two-tier Lube Sheep bento can be microwaved without the lids. It doesn't have any silicone sealants on the lids, but the heat would likely warp them. I think a short zap with the lids would still probably be okay. My sister's Hakoya boxes clearly say not to microwave, but those are more expensive and definitely different material than the Lube Sheep boxes. I think microwaving would damage the decorations.

Lube Sheep boxes tend to be really cheap if you find the right Ebay seller (I find FULL sets for $10), so I would recommend one of those if you plan on microwaving your bento. That way, if you have a microwave accident, it won't be a huge loss.

Most of my boxes are actually the Lube Sheep brand. The packaging and/or the purchase description said not to microwave them. I admit that I have nuked them once in awhile. While it didn't destroy the box (not yet, at least), if it's not meant for microwaving I have some concern that the heat could release whatever odd plastic chemicals into my food. I wouldn't be that concerned except for the fact that I'm breastfeeding and don't want the bambino to get toxic stuff. I'm also thinking ahead for his lunches.

Thanks for the other suggestions. I welcome any other ideas people have :)

Most boxes can be microwaved. Whatever site you buy from will have microwavable boxes. I've trawled through the Casabento and Bento&co online websites and there are microwavable boxes on there. As you're based in the states, I'm sure the daiso online store also has a selection of microwavable boxes too.

The donburi bowl bentos at jlist say they're microwaveable, again without the lids. I just ordered a couple for my house and will report back if something goes awry.

This may not be a practical solution for you, but I am an epidemiologist and am concerned about the health effects of warming plastic (so much about the long-term effects of estrogen-mimicking phalates is still not known - and the things that are known are not very encouraging: http://tinyurl.com/yanne8b (they include breast cancer). Because microwaving food is something we do daily, it's a cumulative exposure I really want to cut back on: in my household, I microwave everything in Pyrex bowls. They come with plastic lids (I remove them). They are available in a great variety of shapes and sizes, and might even work for a light commute.