soman, colorless liquid used as a nerve gas. It boils at 167°C;, evolving an odorless vapor. It is rapidly absorbed through the skin; death may result within 15 min of exposure. In nonfatal concentrations it is hazardous to the eyes. Soman is more powerful than tabun, acting faster and at lower concentrations. Chemically, soman is fluoromethylpinacolyloxyphosphine oxide.