DO NOT microwave a mason jar with an Intelligent LID Storage Lid screwed onto the jar. Just like heating any jar with contents enclosed, you run the risk of the jar contents overheating and exploding.

DO NOT microwave a jar with a DRINK LID with the DRINK SLIDE in the CLOSED position. Again, if the slide is closed and the contents are overheated it can cause the jar to explode.

Intelligent LIDS are made from Polypropylene #5 which is regarded by the FDA as safe in the microwave. If you do want to put a lid in the microwave we suggest you do as follows:

Leave the lid sitting on top of the jar to act as splatter control. DO NOT screw the lid onto the threads. DO NOT overheat the contents.