WEATHERFORD, Okla. –

An anhydrous ammonia spill from an Airgas tanker truck in Weatherford sent 34 people to the hospital on Thursday. Health dangers can be critical for people exposed to the gas.

Emergency officials reported that several victims required intensive care, with some first responders reporting chemical burns in their airways.

A spokesperson for the company which owns and operates the truck, Airgas, has refused to answer questions from News 9.

EPA officials are working with Oklahoma’s Department of Environmental Quality to monitor the environmental impact of the spill.

By Thursday afternoon, EPA officials reported that air quality had returned to normal.

A water sample the same day from Timber Creek returned with a normal pH level of 7, while a nearby soil sample returned a pH level of 10. EPA officials emphasized the soil pH will neutralize over a short period of time.

The EPA was unavailable for an interview Thursday or Friday.

But, OU professor of environmental science and chemistry, Mark Nanny, explained how ammonia affects the environment.

“Liquid ammonia and gaseous ammonia is very toxic to aquatic organisms,” Nanny said. “To give you an idea of how toxic it is: imagine you take a nickel — it’s 5 grams. You cut it up into 5,000 pieces. And if you take 31 of those pieces, and put it into a gallon of water, that will kill half the fish in 96 hours. That’s what we call the lethal concentration of 50%.”

However, Nanny said there are practical and effective methods at preventing that level of harm to an aquatic environment.

“As I understand, they were spraying down the parking lot, which is what they want to do,” he explained. “You want to dilute the ammonia, but you also don’t want it going into the storm drains into the streams. I read they’re putting up berms to try and keep it from dispersing too far.”

Nearly 2.5 million gallons of water was used to contain the ammonia spill. An EPA spokesperson confirmed that earth berms were used to block storm drains that led to Timber Creek.

“It sounds like they’re doing everything that they possibly can,” Nanny said.

Nanny said he doesn’t foresee long-term environmental implications from this incident.

“It’s very volatile,” he said. “It’s going to evaporate. There’s not a continual input into the environment. So, even if it does get into the soil, or gets into the water, yeah — there will be that immediate acute toxicity. You’ll see bad things happen. But, as the ammonia gets neutralized, or volatilizes, the system will go back to normal.”