We report a mass spectrometric study of the hydrogenation of pure C60 in thin solid films. The reactions were performed in vacuum by exposing C60 films to atomic hydrogen, which covalently binds to individual fullerene molecules, resulting in C60Hn (n = 2 to >24), with a wide distribution in n for a given exposure. Fragmentation of the fullerene cages, which for pure C60 proceeds by losses of multiples of two C atoms, is redistributed for C60Hn to include losses of odd numbers of C atoms, though the total degree of fragmentation is unchanged.