Diisopropyl ether is secondary ether that is used as a solvent. It is a colorless liquid that is slightly soluble in water, but miscible with organic solvents. It is used as an extractant and an oxygenate gasoline additive. It is obtained industrially as a byproduct in the production of isopropanol by hydration of propene. Diisopropyl ether is sometimes represented by the abbreviation 'DIPE'. Diisopropyl ether is secondary ether that is used as a solvent. It is a colorless liquid that is slightly soluble in water, but miscible with organic solvents. It is used as an extractant and an oxygenate gasoline additive. It is obtained industrially as a byproduct in the production of isopropanol by hydration of propene. Diisopropyl ether is sometimes represented by the abbreviation 'DIPE'. Whereas at 20 °C, diethyl ether will dissolve 1% by weight water, DIPE only dissolves half as much. It is used as a specialized solvent to remove or extract polar organic compounds from aqueous solutions, e.g. phenols, ethanol, acetic acid. DIPE is used as an antiknock agent. Diisopropyl ether can form explosive peroxides upon standing in air for long periods. This reaction proceeds more easily than for ethyl ether, due to the secondary carbon next to the oxygen atom. Antioxidants can be used to prevent this process. The stored solvent should therefore be tested for the presence of peroxides more often (recommended once every 3 months for diisopropyl ether vs. once every 12 months for ethyl ether). Peroxides may be removed by shaking the ether with a solution of iron(II) sulfate. For safety reasons, methyl tert-butyl ether is often used as an alternative solvent.