"Ethers are relatively stable and unreactive in many respects, but some ethers react slowly with the oxygen in air to give peroxides, compounds that contain an O – O bond. The peroxides from low-molecular-weight ethers such as diisopropyl ether and tetrahydrofuran are explosive and extremely dangerous, even in tiny amounts. Ethers are very useful as solvents in the laboratory, but they must always be used cautiously and should not be stored for long periods of time."