Air separation technology has continued to evolve from cryogenic distillation to a variety of adsorption and other types of processes. Corrosion problems are encountered in the front-end compression and cooling steps where moisture is removed from the air. Thereafter, the main materials concerns are assuring adequate strength and ductility at cryogenic temperatures and preventing fires when handling purified oxygen. Catalytic reforming and partial oxidation technology are used to form syngas from hydrocarbons. Caustic stress corrosion cracking of stainless steels has been a concern in areas where steam is superheated and in dead legs where potassium hydroxide from the reforming catalyst has accumulated. Corrosion fatigue has also been a problem where temperature cycling occurred. A variety of other materials issues are discussed.