Oxygen concentrators leverage common technology to pull oxygen from the air and deliver it on demand. The selective adsorption of the components of air by naturally occurring zeolites has been common knowledge in the scientific community for over 40 years.2Adsorption—not to be mistaken with "absorption" is the binding of molecules to a surface, rather than the filling of pores in a solid. And unlike absorption, the binding to the surface through adsorption is usually weak and reversible.4, 5 It is the adsorption of zeolite structures that provides the foundation for the oxygen molecular sieves used in oxygen concentrators.2 Although many types of zeolites occur naturally, industrial research has paved the way for production of synthetic zeolite structures that are more rigid and provide uniformity in consistency and performance.2 To produce oxygen, concentrators draw room air into the machine via a compressor and through a series of filters to remove dust and bacteria.6 The compressed air is then passed into a column which contains a zeolite molecular sieve composed of aluminum silicate. Nitrogen from the air binds itself to the zeolite through adsorption, while oxygen passes through the sieve. Just before the zeolite fully saturates with nitrogen, the flow of room air is switched to a second column and the first column is vented and back flushed with a small flow of oxygen from the alternate column. The two columns alternate to avoid saturation of the molecular sieve and produce a consistent flow of USP 93% oxygen, which passes through a small reservoir, and a flow control system to be delivered to the patient or anesthesia delivery system.7, 8