It was the hydrogen peroxide (oxidant) that was the dangerous stuff. I remember seeing open cuts foam when my parents put in on me. And that was highly diluted stuff - 5%?
The fuel was methanol alcohol, with the other nasty sounding ingredients added in as a catalyst for the instant combustion.
The most ironic part was that the Germans were aware of the caustic effects of H2O2, so they provided the pilots with a synthetic flight suit - that wasn't liquid-tight. With all its other idiosycracies, the Komet was more of a dangerous stunt than a useful bomber interceptor.