"It's highly corrosive. It's an inhalation hazard. It robs the oxygen out of the air as well as moisture. You cannot breathe. It's highly potent."
And that's why emergency personnel were concerned about the situation in Stewardson just before six Tuesday morning.
They say a truck offloading approximately twenty and a half tons of anhydrous ammonia encountered a problem unloading the compound.
That problem caused the truck to release almost all of the product into the air and on the ground.
"200 people had to evacuate."
The cloud of gas created an obstacle for responding fire departments.
"It's a really helpless feeling to stand there, and look at a cloud and know that there's people on the other side, that you can't get to."
First responders say anhydrous ammonia, when inhaled directly, has the potency to cause major respiratory damage.
"It could be fatal ... Luckily ... this time it wasn't."
Officials say about thirty people went to the hospital for minor respiratory issues.
Emergency responders say it took three hours to contain the fumes, and Stewardson Mayor Paul Antrim says the town couldn't have been in better hands.
"Knowing that the appropriate people were in the appropriate places. That was a relief to me."