Expandable graphite is characterized by its layered graphite structure. By injecting sulfur or nitrogen compounds between the carbon layers and then applying heat, the layers separate like an accordion, causing the particles to expand hundreds of times their original size. This process results in what is known as expandable graphite. 

Upon exposure to high temperatures, expandable graphite can instantaneously expand 70 to 300 times its original volume. This makes it highly effective in blocking and dispersing flames in the event of a fire. 

Expandable graphite, known for its high flame retardancy, is extensively used in a variety of materials. These include flame retardant plastics, flame retardant EPS, PU foam, resins, textiles, and rubber roofing materials. 

This material contributes to increased safety in fire situations.