- Hydrogen Cyanide (HCN): A volatile liquid that can disperse as a gas. It is highly toxic and can cause death within minutes. - Cyanogen Chloride (CK): More toxic than hydrogen cyanide and can cause severe irritation in addition to its asphyxiating effects. - Arsine (AsH3): A gas formed from arsenic that causes hemolysis (destruction of red blood cells), leading to renal failure and death.