The oxygen generation composition utilizes magnesium oxide to modify and smooth the oxygen generation rate, suppress chlorine formation, improve the rheology and uniformity of performance of an operating chemical oxygen candle, and to facilitate the mixing of the candle ingredients. The oxygen generation composition typically comprises a metal powder as a fuel; magnesium oxide; and an oxygen source selected from the group consisting of alkali metal chlorates, alkali metal perchlorates, and mixtures thereof. The composition can also include a transition metal oxide catalyst, and can include a binder.