A pile of Pyrex bowls
How Safe Is It To Use Vintage Pyrex In The Oven?
Made from borosilicate glass, vintage Pyrex is generally considered safe to use in the oven compared to those made from tempered glass, but there are still precautions to take.
All Pyrex manufactured before the 1950s was made from borosilicate glass, which is exceptionally resistant to thermal shock, meaning it can withstand rapid temperature changes.
When exposed to high heat, borosilicate glass expands less compared to tempered glass, making it less prone to breaking. It is the same type of glass used in laboratory equipment.
Tempered soda-lime glass is more susceptible to thermal shock, so it expands more when exposed to heat. This increases the risk of shattering when transitioning from temperatures.
To further ensure safe use when using vintage Pyrex, bring it to room temperature before placing it in the oven, as placing cold glass in a hot oven can stress the material.