... but also be a courtlike arts and crafts which often used as gifts for personal or commercial purpose. Charcoal Crafts Function 1 ... air such as carbon monoxide, formaldehyde, benzene and similar gas, ammonia, niton, sulfur dioxide and other smog or smell to purify air ... high density, big granule polluted circumstance such as building site, industrial factory etc. 4. Clean the surface of charcoal crafts ...