The benefits from fire use - including hazard reduction, silvicultural manipulation, pathogen control, and nutrient recycling - might be forfeited by public reaction to smoke, whether harmful or not. Generally, the public desires alternatives to burning, but might accept fire if direct control of emissions were possible. The effects of diammonium phosphate (DAP) and ammonium sulfate (AS) on particulate emission and fire intensity were investigated. Particulate emission rate and total quantity were increased by DAP to several times those produced from the control. Inversely, very little increase was observed for AS. Since burning rate for AS-treated fuels was also decreased, this retardant might be useful in smoke control through extension of burning periods.