I put the cans immediately after receipt in the dishwasher. In addition to the cans was just a plate with a tomato sauce remains in the machine. After rinsing cup had an orange stain. That in itself would now not really bother me, but I have used 2 cans for a pizza sauce and frozen, thawed and briefly placed in the microwave. After that both doses of interior rough, white spots, who left neither in the dishwasher, even with much scrubbing had. It felt as if the plastic broke down at these points. Have thrown away after use 1x the two doses. Very sad, of Avent I expected more! If I einfriere in future porridge in these containers, I'll probably have a rain wear on cans when they go as fast broken. :(