Oven doors break primarily for two reasons: the type of glass used and imperfections within the glass. Most ovens use tempered soda-lime glass, which is less tolerant of thermal changes, or more durable borosilicate glass.

However, small imperfections such as nickel sulfide inclusions can cause glass to break spontaneously, especially during high heat cycles such as self-cleaning. To prevent such incidents, it is important to handle oven doors carefully, avoid using abrasive tools or placing heavy objects on the door, and ensure that containers inside the oven do not touch the glass.

Taking simple precautions, such as using gentle cleaning tools and avoiding sudden temperature changes, can significantly reduce the risk of breakage, keeping your cooktop safe and your oven in good working order.