Greenergy Thermal Insulation Wool Best Raw Cotton Refractory Bio Soluble Fiber Bulk. Bio Soluble Safety: Asbestos and ceramic fiber-free; dissolves in bodily fluids for lung safety. Customizable Width: Width is available in customized dimensions to fit specific application needs. Low Thermal Conductivity: Exhibits very low thermal conductivity and heat storage for efficient insulation. Flame Retardant: Features flame retardant properties suitable for fire seals and boiler insulation. Lightweight and Flexible: Made from spun calcium magnesium silicate fibers for easy handling and installation. Versatile Applications: Ideal for boiler insulation, chimney fill, heaters, and wood burning stoves.