Recently observed non-proton hydrate ions observed at 37 km by Arnold, B¿hringer and Henschen are interpreted as being protonated sodium hydroxide cluster ions of the form NaOH2+ (H2O)n (NaOH)m. Values of n from 0 to 4 and m from 0 to 2 allow an interpretation of all seven unidentified NPH ions reported by Arnold et al. the sodium oxide molecules believed to exist below the well-known sodium layer around 90 km are presumed to convert to the more stable NaOH molecules below ~40 km where the OH/H and HO2/H concentration ratios become very large. The very large proton affinity of NaOH (~248 kcal mol-1) virtually assures proton transfer from the H+(H2O)n ions that are produced in the stratosphere and observed to be dominant above ~40 km. The possible role of other metallic species in stratospheric ion chemistry is briefly discussed.