Table 3. Half-Life of Superoxide Decay by Spontaneous Disproportionation or Disproportionation Catalyzed by SOD.

[O2•–] (M)	[SOD] (M)	t1/2	acceleration factor
10–6	none	3000 ms
10–6	10–9	175 ms	20×
10–9	none	hours
10–9	10–9	175 ms	10 000×
10–9	10–6	0.175 ms	10 000 000×