Insulation made using a fire-retardant substance or material is called fireproof insulation. It is used in a variety of places in a variety of ways. For example, it is not just used in building materials, but also in clothes for fire resistance, and to insulate the fireplace in a house in order to ensure fire safety. Fireproof insulation can be produced in two ways; either by using special chemical substances or materials, or by coating regular insulation materials in a layer of fire-retardants to make them fireproof.
Fire-retardants can be used on almost any kind of material, and an application of a fire-retardant can work in different ways. However, its main function is to make the material less combustible and difficult to burn. It offers resistance from fire in various ways; it could either form a layer of carbon char when something is burning, it could prevent the material from burning by forming a non-flammable layer for protection, or extreme heat could cause a chemical reaction wherein―to dilute combustible substances or gases―it releases water vapor and slows down the burning rate. Fire-retardants are also used in fire blankets that are used to extinguish small fires.
The materials come in different forms such as foam, film, foil, chopped fiber, glass wool, polymer, fibrous mats, and in a board or block. The board is further made into sheets and strips, fibers are pressed into a mat by braiding, weaving, knitting, or pressing it into the mat using adhesive. Almost all insulation are rated fireproof; but, most of them only resist fire and are not effective beyond a certain temperature.
Each type of insulation is characterized with 'R value' which indicates the heat resistance of a particular material. If used for temperatures beyond their resistance, the material may break down, become ineffective, and will have to be replaced with a new one. Buying new insulation is a costly affair, and therefore you must familiarize yourself with the temperatures that each of the materials can resist in order to not have to buy a new one.
Fiberglass: Fireproof fiberglass insulation can be used for temperatures up to 100º C or 212º F.
Polymer: Polymers can be used for temperatures up to 1215º C or 2220º F.
Glass Wool: Glass wool is good to be used at temperatures falling between the range of 100º C to 660º C or 212º F to 1220º F.
Asbestos: Asbestos can be used for temperatures exceeding 1649º C or 3000º F.
Cellulose: Although cellulose is not a very effective material for insulation, it can be used for fire resistance for temperatures upto 149º C or 300º F.
Before you decide to install fireproof insulation, it is imperative to check the temperatures that can be handled by the materials. It's a costly deal and you don't want it to be ineffective.