Aspects of the electron paramagnetic resonance (EPR) spectra Of C-60(n) fulleride ions (n = 2, 3) and the EPR signal observed in solid C-60 are reinterpreted, Insufficient levels of reduction and the unrecognized presence Of C120O, a ubiquitous and unavoidable impurity in air-exposed C-60, have compromised most previously reported spectra of fullerides. Central narrow line width signals ("spikes") are ascribed to C120On- (n = odd). Signals arising from axial triplets (g similar to 2.0015, D = 26-29 G) in the spectrum of C-60(2-) are ascribed to C120On- (n = 2 or 4). Their D values are more realistic for C120O than C-60. Less distinct signals from "powder" triplets (D similar to 11 G) are ascribed to aggregates of C120On- (n = odd) arising from freezing nonglassing solvents. In highly purified samples of C-60, we find no evidence for a broad similar to30 G signal previously assigned to a thermally accessible triplet of C-60(2-). The C-60(2-) ion is EPR-silent. Signals previously ascribed to a quartet state of the C-60(3-) ion are ascribed to C120O4-. Uncomplicated, authentic spectra of C-60(-) and C-60(3-) become available when fully reduced samples are prepared under strictly anaerobic conditions from freshly HPLC-purified C-60. Solid off-the-shelf C-60 has an EPR signal (g similar to 2.0025, DeltaH(pp) similar to 1.5 G) that is commonly ascribed to the radical cation C-60(.+). This signal can be reproduced by exposing highly purified, EPR-silent C60 to oxygen in the dark, Doping C-60 with an authentic C-60(.+) salt gives a signal with much greater line width (DeltaH(pp) = 6-8 G). It is suggested that the EPR signal in air-exposed samples of C-60 arises from a peroxide-bridged diradical, .C-60-O-O-C-60(.) or its decomposition products rather than from C-60(.+). Solid-state C-60 is more sensitive to oxygen than previously appreciated such that contamination with C120O is almost impossible to avoid.