Pyrex is oven safe. It is also dishwasher safe, microwave safe and suitable for freezing. A Pyrex dish can be placed directly into the oven or microwave from the refrigerator but should not be placed on a direct heat source, such as a gas or electric stovetop.
Pyrex is a heat-tempered glass originally developed by Corning Glass for use in railroad lanterns. Traditional glass often shattered when the heat from the light source met the cold from the outdoors. Pyrex was designed to withstand such temperature fluctuations. It was first used as cookware when a Corning scientist brought sawed-off jar bottoms home for his wife to use as casserole dishes.
Pyrex is easy to clean and care for, and its nonporous construction resists stains and odors. Pyrex cookware and bakeware are available in a range of sizes and styles, including casserole dishes with fitted lids for storage. The glass is very durable and resistant to chips and cracks, but it can shatter if dropped onto a hard surface.
When purchasing Pyrex glassware, buyers should examine the clarity, shape and uniformity of the glass to ensure the piece is of the best quality. Holding the piece against a solid-colored surface checks for waves, color impurities and other inconsistencies that could indicate weaknesses in the glass.