Layered glass consists of two or more airtight glass plates glued to each other with one or multiple transparent PVB safety films in between. The safety film keeps the glass splinters together in case of breakage, resulting in them not being released. The more safety films, the more the glass becomes burglarproof. Hardened glass has undergone a special thermal treatment, causing it to be much stronger than normal glazing. This type of safety glass is used less than glazing and rather for glass tables, glass doors… Fire-resistant glass is, just like layered glass, constructed from multiple layers with fire-retardant gel in between. There are various different types of gel, each with its own retardant that may increase to 90 minutes. This type of glass is available with or without metal/wood frames or intermediary styles (Pyrobel VisionLine).