A wash bottle is a squeeze bottle with a nozzle, used to rinse various pieces of laboratory glassware, such as test tubes and round bottom flasks. Wash bottles are sealed with a screw-top lid. When hand pressure is applied to the bottle, the liquid inside becomes pressurized and is forced out of the nozzle into a narrow stream of liquid.
Most wash bottles are made up of polyethylene, which is a flexible solvent-resistant petroleum-based plastic. Most bottles contain an internal dip tube allowing upright use. Wash bottles may be filled with a range of common laboratory solvents and reagents, according to the work to be undertaken. These include deionized water, detergent solutions and rinse solvents such as acetone, isopropanol or ethanol. In biological labs it is common to keep sodium hypochlorite solution in a wash bottle to disinfect unneeded cultures.