It's safe from both microwave and freezer for easy heating up and cooling. The mask holds lavish gel beads and can be microwaved for 30 seconds to achieve 90 minutes of heat or frozen to get 3 full hours of cold compress. It's recyclable and non-toxic and will not break when dropped. Direction are printed on the opposite side. PRECAUTION: merchandise will be HOT after microwaving. condensation may potentially induce foaming until cool