Before revision: 250px|Smouldering combustion in glowing embers of barbecue coal briquettes Smouldering (British English) or smoldering (American English; see spelling differences) is the slow, low-temperature, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase URL "Smoldering Combustion" by T.J. Ohlemiller, SFPE Handbook of Fire Protection Engineering (3rd Edition),2002 Many solid materials can sustain a smouldering reaction, including coal, cellulose, wood, cotton, tobacco, cannabis, peat, plant litter, humus, synthetic foams, charring polymers including polyurethane foam and some types of dust.
After revision: 250px|Smouldering combustion in glowing embers of barbecue coal briquettes Smouldering (British English) or smoldering (American English; see spelling differences) is the slow, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase URL "Smoldering Combustion" by T.J. Ohlemiller, SFPE Handbook of Fire Protection Engineering (3rd Edition),2002 Many solid materials can sustain a smouldering reaction, including coal, cellulose, wood, cotton, tobacco, cannabis, peat, plant litter, humus, synthetic foams, charring polymers including polyurethane foam and some types of dust.