Our OXO Tot Glass Baby Blocks were created with as much love and attention as the homemade baby food youâre going to store inside them. We made them out of durable borosilicate glass, which means they can go directly from the fridge or the freezer into the oven or microwave. We also added easy-to-use, leakproof SNAP lids, and designed a tray for fridge and freezer storage. The only thing we didnât do was puree the peas.