A number of mechanisms can result in the generation of spurious tones in Orthogonal Frequency Division Multiplexing (OFDM) receivers. In this work we determine the Signal-to-Noise-Ratio (SNR) degradation at the output of the Fast-Fourier-Transform (FFT) block and evaluate the performance of a Digital Audio Broadcasting (DAB) receiver in the presence of such tonal interference. We show that the degradation varies with the central frequency of the interference and demonstrate that relatively weak spurious tones can compromise the performance of a DAB receiver. We provide specific evaluations of the severity of the above effect for all possible DAB systems parameterizations and evaluate the permissible levels of spurious tones in such systems. It is shown that for DAB EEP Mode A protection level 4, tonal interference of 14 dB lower than the signal can compromise the receiver performance.