Refrigerator Shelf Repair

Use some baking soda for a filler and a few drops of Mister Glue.  Build it up in layers bit by bit if necessary to fill the gap and hold everything together.  Mister Glue will wick or soak into the baking soda and make it extremely hard and will hold the two sides together.  With a split in the plastic shelf like this you may want to add some baking soda and glue to both sides of the split.