That does not conduct (electricity or heat).(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "nonconducting" in a sentence
"If possible, stand on something dry and nonconducting, such as a mat or folded newspapers."
"Electrical wires can also produce heat and fire if they are left bare—without nonconducting insulation—near flammable material, such as wood or sawdust."
"In this type of fire, therefore, the extinguishing agent should be nonconducting."