A potential growth area for hydrogen demand lies in environmental applications; for example, the treatment of organic liquids contaminated with halogens, sulfur, nitrogen, oxygenates, or organic metals. The treatment involves the introduction of hydrogen to the contaminated liquid at elevated temperatures and pressures and passing the mixture over a selective catalyst. Here, the contaminants react with the hydrogen and are separated from the hydrocarbon mix.This process is particularly effective for wastes containing chloride, such as spent chlorinated solvents or vinyl chloride monomer residues, where the chloride can be removed and converted into hydrogen chloride. In oxygenated waste, such as propylene oxide by-products, the oxygen can be removed and converted to water.

Hydrogen may also be used as a calibration gas for instrumentation and in a wide variety of applications requiring controlled atmospheres.