Diethylhydroxylamine (DEHA) has been utilized as an oxygen scavenger in boiler systems in many industries for the past 20 years. Its unique combination of properties, such as volatility; the ability to passivate steel surfaces and its very low toxicity makes it the oxygen scavenger of choice for many applications. The application of DEHA in a number of different systems is discussed in this article and its performance is compared with hydrazine and sulfite. Deha Performance Characteristics DEHA has a number of beneficial properties as an oxygen scavenger in boiler feedwater systems: 1. Rapid complete oxygen removal under typical boiler feedwater temperature and pH conditions. 2. Promotes passivation of internal surfaces in the boiler system. 3. It is volatile similar to a neutralizing amine with the ability to distilled off the boiler, and is available to protect the entire steam condensate system as well as the feedwater and boiler system. 4. Under the action of heat, some of the DEHA is degraded to yield two neutralizing amines which assist in elevating the pH in the condensate. 5. It has very low toxicity making it safe and easy to handle in typical boiler application systems.