Carbon monoxide is a highly poisonous, odorless, colorless, and tasteless gas. It is very flammable in air over a wide range of concentrations (George 2001) and burns in air with a bright blue flame (O'Neil et al. 2006). It becomes a liquid at 81.62 K (-191.53 °C) and is insoluble in water above 70 °C (George 2001).