Video of Arizona Nitric Acid Spill Shows Hazardous Smoke Spread for Miles

Video footage of an upturned truck on a highway in Arizona has been viewed more than 2 million times, showing toxic orange gas spewing out into the atmosphere.

According to the Arizona Department of Public Safety (ADPS), a collision occurred involving a commercial truck hauling "2,000 pounds" of nitric acid at around 2:43 p.m. local time (4:43 p.m. ET). The incident occurred on Interstate 10 between Rita Road and Kolb Road, southeast of Tucson.

Two hours later, the department's Unified Command evacuated people within a half-mile of the incident and directed those within a mile to shelter in place. This second order was lifted at 10:45 p.m. ET, and the evacuation order will follow at 8 a.m. on Wednesday.

Arizona toxic nitric acid spill
Members of the Tucson Fire Department's hazmat team attend a toxic spill of nitric acid on the Interstate 10 on February 14, 2023. The chemical is acutely toxic and can be fatal if inhaled. Tuscon Fire Department

According to the National Library of Medicine, nitric acid is acutely toxic and can be fatal if inhaled, as well as being corrosive and able to decompose flesh.

Exposure to the noxious chemical can cause eye and skin irritation, as well as fluid in, and inflammation of, the lungs, and bronchitis, the Centers for Disease Control says.

Nitric acid is used in the manufacturing of fertilizers, explosives and dyes, as well as the production of some plastics.

Marc Glass, the principal environmental consultant at Downstream Strategies, who has advised state and federal projects on contamination in West Virginia, told Newsweek that though nitric acid was "very reactive" and could damage lung tissue, its reactivity meant it would react with the oxygen in the air, forming particulates such as nitrous oxide, and so the risk would dissipate "relatively quickly, in a matter of hours after the spill."

"There wouldn't necessarily be a breathing hazard outside of that radius for very long," he added.

The Pima County Sheriff's Department instructed people at the University of Arizona Science & Tech Park—located a short distance from the crash site—to evacuate, along with others in the area. This was "out of an abundance of caution," news channel KKTV reported.

The Tucson Fire Department said that its hazmat team was placed on the scene to "control the hazmat and brush fire."

The ADPS said on Tuesday evening that the driver of the truck had died, though the cause is unclear. Newsweek reached out to the ADPS for further comment.

Glass warned that the nitric acid could react with the soil, dissolving it and freeing up "naturally-occurring heavy metals such as arsenic" and "put them in solutions."

"There could be a really big impact to the groundwater in that area, with a lot of metals mobilizing into the groundwater," he said.

A regional EPA spokesperson said ADPS had declined EPA assistance with the incident, but added: "It is also EPA's understanding that the hazardous materials have now been removed from the truck and dirt is being utilized to mitigate further off-gassing."

The spill comes just two weeks after a train derailment on the border of Ohio and Pennsylvania on February 3 led to a toxic release of chemicals into the air and surrounding environment.

Residents of East Palestine, Ohio, were evacuated so emergency responders could undertake a controlled burn of the vinyl chloride in five rail cars to avoid a massive explosion. However, it released the toxic gases hydrogen chloride and phosgene into the air.

Since the spill, the Environmental Protection Agency (EPA) detected several toxic substances in the soil and a nearby waterway. Residents have complained of symptoms associated with exposure to contaminants.

In the latest incident, the ADPS said that Interstate 10 had been shut in both directions. State troopers expected "an extensive closure." As of 4 a.m. ET Wednesday, the road remains closed.

The Arizona Department of Transportation said there was no estimated timetable for reopening the freeway. The ADPS warned commuters to "anticipate an impact on their Wednesday morning commute."

When asked to comment, the Arizona Department of Environmental Quality directed Newsweek to the ADPS updates.

Update 02/15/23, 12:24 p.m. ET: This article was updated to include comments from Marc Glass.

Update 02/16/23, 08:20 a.m. ET: This article was updated to include comment from the EPA.