Fireproof materials are found in homes, commercial structures, cars and even some products. Modern fireproof materials are generally considered safe and will prevent fires from spreading under a defined set of circumstances.

Things that are fireproof are different than those that are “fire retardant”. Fire retardant materials are designed to burn at a slower rate, whereas fireproof materials shouldn’t burn at all under normal conditions.

How Fireproof Materials Work

Fireproof material reduce the flow of heat through the thickness of the material.

While some materials are certified as “fireproof”, no material is actually 100% fireproof because all materials eventually will burn if it reaches a high enough temperature. For example, a fireproof material that is at the epicenter of a nuclear explosion will certainly burn and vaporize.

Fireproof Refractories

Materials that are hard and heat resistant — such as cement, bricks, ceramics, and fire clay — are known as refractories. Usually they are made of alumina, chromite, fire clays, magnesite and silicon carbide.

These types of materials usually are used in high-temperature applications, such as in furnaces, reactors and processing units. They also are commonly used in electrical and thermal insulation.

Fireproof Fiberglass

Fireproof fiberglass is made mostly of glass and sand. Its raw materials include silica sand, limestone, soda ash and sometimes calcined alumina, borax, feldspar, nepheline syenite,  magnesite and koalin clay.

Fiberglass if formed by forcing molten glass through a sifter, which spins it into threads that are bonded together, creating a strong, durable and naturally fireproof material.

Fireproof fiberglass is divided into different types for different applications. For example, Type E (electrical) is used in electrical insulation tape. Type T is used for thermal insulation.

Mineral Wool and Glass Wool

Mineral wool and glass wool are frequently used as fireproofing materials because they are not good conductors of heat or sound, are non-combustible and have high melting temperatures. They also are insect-proof, which makes them idea for building materials that might otherwise be targeted by termites.

Asbestos was formerly used widely as a fireproofing material until it was discovered that it was linked to various forms of cancer, such as mesothelioma.