This type of lab flask can be used for many tasks in a laboratory in addition to mixing and heating. These can include cooling, incubation, filtration, and storage. Certain plastic flasks can be autoclaved for sterilization. Erlenmeyer flasks are used to contain liquids and for mixing, heating, cooling, incubation, filtration, storage, and other liquid-handling processes. Their slanted sides and narrow necks allow the contents to be mixed by swirling without the risk of spills, which is useful for titrations and for boiling liquids.