In a perfect world, we would remember to take out that plastic freezer bag of spaghetti sauce out of the freezer the night before we need it. But more often than not, we end up grabbing a frozen freezer bag of sauce about half an hour before we want dinner on the table. But is it really safe to microwave freezer Ziploc bags?
Fortunately, if you are defrosting something you have frozen in a plastic freezer bag, it is safe to use. They will not release any harmful dioxins when you are defrosting.
If you do defrost anything frozen in a freezer bag, do remember to open a corner of the zip to allow any steam to escape. It is trapped steam inside that can cause plastic to melt in the microwave.
You do need to worry about leakage when defrosting in the microwave, so place the bag on a plate or other microwave safe dish or container. Then halfway through defrosting, you can also transfer the contents of the bag into the container if you’d like. This would be especially useful if the contents of the bag are more liquid than solid.