From http://afsf.lackland.af.mil/Organization/AFSFC/SFP/AF%20Pubs/VEHICLE%20BOMB%20MITIGATION%20GUIDE.PDF
referenced on cryptome: >> Another fertilizer-based explosive used by terrorists is Urea Nitrate (its components are urea, sulfuric acid, nitric acid, and sodium cyanide). << As is well known, and used in execution chambers, mixing a cyanide salt with an acid releases HCN, a lethal blood gas. Nitration of various materials (e.g., glyercin, etc.) does not require cyanides, but only strong concentrations of H2SO4 and HNO3. This is anarchists-cookbook-style disinfo.