Solarmite

Solarmite was an explosive substance. The modified CCPC, Pain-Maker, was loaded with solarmite so when he was fired on by K9 Mark 2, he would take K9 with him. However, K9 refused to fire and escaped before Pain-Maker self-destructed. K9 would later say that while solarmite would damage him, the only explosive force capable of destroying him was his own self-destruct function. (TV: Robot Gladiators)