Is All Glass Oven-Safe?

Now we're cooking with glass – but only if it's oven-safe, of course. While some glassware can go in the oven, glass that hasn't been properly treated can explode or shatter if exposed to high heat. Standard glass products, including most cups, mugs, and plates, should never be used for cooking. They can break at relatively low heat, around 300 degrees Fahrenheit, and can't withstand sudden temperature changes. When they break, they shatter into large, sharp pieces that can cause injury.

So what glass is safe to put in the oven? Generally speaking, tempered glass, Pyrex-branded glassware (a brand known for its shatter-proof glassware products), and borosilicate glass are designed to withstand oven temperatures. Before baking, always check the label or packaging to confirm the item is oven-safe. If in doubt, contact the manufacturer or look up the product online to confirm if it is oven-safe. Above all, never put glass in the oven unless you're confident it can safely withstand the heat.

Even oven-safe products should be used according to specific guidelines. One common cause of breakage is thermal shock, which happens when glass experiences a rapid change in temperature. Placing cold glassware in a hot oven, for example, can cause even tempered glass to shatter, so don't move your pan directly from the fridge or freezer to the oven. 

While Pyrex and tempered glass products are safe for the oven, they should never be used on stovetops, as they were not made to withstand direct heat (this risk that also applies to stoneware products). Certain glass cookware can be used on the stovetop, but always make sure your glass pot is labeled stove-safe before cooking. And even items with a stove-safe designation can break if not used properly. Gas stovetops, for instance, can produce uneven heat, which can cause thermal shock. To prevent this, use a heat diffuser to evenly heat your pot. If you're using an electric stove, monitor the temperature carefully because these stoves can get very hot, and some glass pans may not withstand the heat. And never cook with glass pots or pan that has visible cracking, as this makes them more vulnerable to breaking.