The Caralight photochemical system reduces the costs of dioxin-furan control for secondary aluminum and secondary copper melting furnaces. Thermal oxidizers are no longer needed. In addition to reducing fuel costs, the Caralight photochemical system eliminates the greenhouse emissions from thermal oxidizers. Systems presently using activated carbon injection for dioxin-furan control can reduce costs by converting to the Caralight photochemical system. The environmental benefits include the elimination of the handling and disposal of activated carbon waste with adsorbed dioxin-furans. In the photochemical system, the dioxin-furans are destroyed, not stored.