 This weak point in the wiring also ran near a junction in an ethylene glycol / water cooling line that had been prone to leaks . The electrolysis of ethylene glycol solution with the silver anode was discovered at MSC on May 29 , 1967 to be a hazard capable of causing a violent exothermic reaction , igniting the ethylene glycol mixture in the CM 's pure oxygen atmosphere . Experiments at the Illinois Institute of Technology confirmed the hazard existed for silver @-@ plated wires , but not for copper @-@ only or nickel @-@ plated copper . In July , ASPO directed both North American and Grumman to ensure no silver or silver @-@ coated electrical contacts existed in the vicinity of possible glycol spills in the Apollo spacecraft . 
