American Gypsum’s patent pending 1/2” M-Bloc Ekcel® Type X gypsum panel was developed as a fire resistant, mold and moisture resistant wallboard for use in the patent pending 2-1/2 hour fire rated ME Area Separation Firewall System. The M-Bloc Ekcel® Type X panel is encased in a mold and moisture resistant blue face paper and brown back paper, that has been tested to the industry’s most rigorous standard, ASTM D3273 (Standard Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental Chamber) scoring a perfect 10, thus minimizing the risk of mold and mildew growth. American Gypsum products contain no asbestos and no detectable levels of formaldehyde.