For over a century, the Pyrex brand has been an expert in the kitchen. With its glass kitchen products, the brand is a major player in the cookware market. Pyrex uses borosilicate glass for its glass kitchenware. This type of glass is known for its sturdiness and the fact that it can take a beating. In addition, the borosilicate glass is resistant to extreme temperatures. For example, Pyrex oven dishes can withstand temperatures between -40°C and 300°C. These properties make the utensils suitable for both the freezer and the oven.