Ammonium nitrate is a chemical compound with the chemical formula NH4NO3. It is a white crystalline solid consisting of ions of ammonium and nitrate. It is soluble in water, and holds water as a solid. It is used as a high-nitrogen fertilizer. Mixing it with fuel oil creates ANFO, a popular industrial explosive which accounts for 80% of explosives used in North America; similar formulations have been used in improvised explosive devices. Many countries are trying to stop using AN, due to the potential for misuse, as well as disasters that have occurred. AN explosions have killed thousands since the 20th century, and countless IEDs have been made and detonated from AN and ANFO. The most recent AN explosion, as well as one of the most notorious, was the 2020 Beirut explosion.