Since I have a microwave and stove at work my wife bought me glass containers with very tight seals. Yes they are heavy in my panniers but I figure I'm in the commute for exercise not racing so it helps with the health. She didn't like me using plastic to heat stuff up in and the dishes at work well we all know what they can be like. Yes glass can break in an accident but the one time I went down I didn't up near the bike anyway.