Arsine

• colourless gas with a faint garlic odour that is produced when metals containing arsenic react with acid
• primarily used in the microelectronics industry - the processing of semiconductors used in computer chips involves the etching of gallium arsenide with acids
• is the most toxic form of arsenic (and that is saying something, since elemental arsenic is a badass carcinogenic and highly toxic metal that'll mess you up something awful)
• Lewisite is an arsine derivative that was developed prior to World War II for use in chemical warfare as a blistering agent like mustard gas
• is a pancytotoxin, meaning that it can mess up every organ in your body
• inhalation of this gas produces, among other things, a fulminant (massive) hemolytic anemia (a substantial loss of red blood cells because a bunch of 'em all go and burst open), likely by inducing oxidative damage such that the membrane integrity of the blood cells is compromised
• the hemolysis in turn leads to nephrotoxicity (hemoglobin in red blood cells is released and precipitates as arsenic-hemoglobin complexes in nephrons, disrupting kidney function) and cardiac affects (red blood cells contain lots of potassium, so when they break open you get lots of potassium released in your blood, which causes conduction disturbances that can lead to heart failure)

Ford M, Delaney KA, Ling L, and Erickson T. Clinical Toxicology. Philadelphia: W.B. Saunders Company, 2001.