Acrylonitrile-butadiene rubber (NBR) latex was hydrogenated using diimide in the presence of selenium catalysts under an oxygen atmosphere. The process has been optimized and is extremely effective in the hydrogenation of NBR latex, with more than 3350 carbon-carbon double bonds reduced per atom of selenium in 5 h at 60 degrees C. The amount of gel formed was controlled with gel inhibitors such as Irganox. This process constitutes a new route for obtaining totally hydrogenated acrylonitrile-butadiene polymer with low amounts of gel and very low amounts of selenium contaminants. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1390-1394, 2010