INDIANAPOLIS - Compressed natural gas is becoming increasingly popular for fueling vehicles, but it's potentially putting firefighters at risk.
Compared to gasoline, CNG doesn't ignite as quickly, but when it does, it will burn rapidly.
Fire departments have to change their response when it comes to fighting compressed natural gas vehicle fires, like the one that shut down Interstate 465 Monday .
Once Wayne Township Fire Fighters realized the INDOT truck was powered by CNG, they had to step back and regroup.
"We try to look for placards on vehicles, but in the case of the fire yesterday, there was so much smoke and fire we wouldn't have been able to see a placard on it anyhow," said Wayne Township Fire Department Captain Mike Pruitt.
Alternative fuels are presenting new challenges and dangers for firefighters and drivers.
Firefighters are now getting constantly updated, special training to deal with ever-changing fuel sources -- including hybrids that can pose a high-voltage risk.
"We can go to the junkyard and we can practice cutting on vehicles all day, but those vehicles tend to be several years older than what we're dealing with with the cars on the street," Pruitt said. "So would we go out into the junkyards and find tons of hybrid cars or natural gas vehicles? Not right now."
Instead, they rely on guide books to tell them how far to stay back depending on the type of fuel, and they try to approach with caution until they know exactly what they're fighting.
Twenty percent of new buses and trucks are fueled by compressed natural gas.
Fire departments in the U.S. respond to a vehicle fire every 2 and a half minutes.