” Some arsenic trioxide finds its way into the air. Condensation with the vapors over a surface area at temperatures above 250° C sorts the glassy modification, which slowly but surely improvements on the crystalline, monoclinic type. In the processing of As2O3 the oxide is normally reduced withcarbon: 2As2O3+3C?→As4+3CO2 The http://https//chemscenter.com