Fire-rated glass refers to glazing that employs the latest technology to prevent glass breakage when exposed to high heat, such as in a fire. Keeping a glass surface intact protects building or room occupants not only from fire but smoke that may accompany the fire. A newer, safer version of wired glass exists, as do other glazing alternatives that are clear and wire free. The actual fire ratings assigned to the glass refer to the length of time the glass can be exposed to heat before it fails. Ratings can be measured in minutes or hours.
Fire-rated glass is either fire protective or fire resistive. Both block smoke and flames but fire protective glazing can still transfer the heat of the fire to the other side of the glass, while fire restrictive glazing does not.
