Crystalline magnesium sulfate heptahydrate (MgSO₄·7H₂O), also known as Epsom salt, is used as an environmentally friendly flame retardant in cellulose insulation. This substance is naturally occurring and non-toxic, making it an attractive alternative to traditional, often chemically produced flame retardants. Cellulose insulation is a cellulose-based material used in building insulation. Magnesium sulfate functions as a flame retardant because it releases water when heated, cooling the material and preventing the spread of fire.
In addition, magnesium compounds such as magnesium sulfate (MgSO₄) and magnesium oxide (MgO) are widely used in the production of fire-resistant materials. Magnesium oxide is a ceramic material with excellent heat resistance, capable of withstanding high temperatures without degrading. This makes it useful in applications such as metallurgy, furnace linings, and industrial fire-resistant structures. Magnesium sulfate, on the other hand, enhances the fire resistance of the material and improves its mechanical properties.
The use of these compounds in fire-resistant materials highlights the focus on finding and utilizing more environmentally friendly alternatives in construction and industry.