The officials testified in Washington Wednesday before a National Transportation Safety Board panel that's investigating the 2012 derailment.
The NTSB has criticized the delay of evacuation orders to Paulsboro residents who at first were told to stay in their homes as vinyl chloride leaked from a rail car.
Paulsboro officials say the chemical would not have harmed residents in their homes who kept doors and windows closed. The officials say that evacuating residents while emergency personnel were responding would have created "more chaos."
Emergency responders also say evacuating the town of more than 6,000 still poses a problem due to lack of transportation.