The latest invention from Thomas FX . . . . BIO-ASH (TM) Realistic Biodegradable Volcanic Ash Particles – fully biodegradable, made of food grade ingredients, extremely realistic, comes in coarse and movie grade (medium); 5 lb box will cover an area of approximately 144 square feet, 1″ deep. This product is ecologically safe, non toxic, non static and fully biodegradable! Call for details.