During a tower plug, EE was using Cardox tubes to dislodge a feed pipe. After the first 2 Cardox tubes misfired, the employee opened the Cardox pot to insert a 3rd Cardox tube. When he opened the pot hot material flowed out the opening causing burns to his forearms and left wrist. He received 2nd degree burns to his left wrist. He was treated & released to restricted duty.