An accident involving a commercial tank truck leaked hazardous materials onto Interstate 10 outside Tucson, Arizona on Tuesday, prompting state police to block traffic on the highway.

Arizona Department of Public Safety via AP

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Arizona Department of Public Safety via AP

An accident involving a commercial tank truck leaked hazardous materials onto Interstate 10 outside Tucson, Arizona on Tuesday, prompting state police to block traffic on the highway.

Arizona Department of Public Safety via AP

TUCSON, Arizona — A portion of a highway that runs through the southern Arizona desert and connects two of Arizona’s largest cities remains closed Wednesday morning outside of Tucson. It was the day after a fatal collision leaked hazardous materials, forcing people to evacuate nearby.

Residents within half a mile of the crash on Interstate 10 southeast of downtown Tucson were evacuated, and those within 3 miles were found to have leaked liquid nitric acid from a truck tractor pulling a box trailer. After they were found to be there, they were ordered to evacuate on the spot. Arizona Department of Public Safety said. The acid sent out eerie yellow and red plumes on the asphalt road through the scrub-strewn dry land.

The one-mile shelter-in-place order was lifted on Tuesday night, but officials reinstated it early Wednesday morning, allowing more nitric acid to escape as the crew tried to widen the perimeter after attempting to remove the luggage. Residents of the area were told to turn off heaters and air conditioning systems that bring in outside air. The area will be monitored to assess the need for changes to these orders, officials said, and those displaced should expect to evacuate until noon, officials said.

Bad weather temporarily hampered nighttime hazard retrieval and mitigation efforts. However, officials said Wednesday morning that the material had been removed from the truck and the crew had been using dirt to prevent nitric acid from being released.

The truck driver was killed, but few other details were released, police said.

The agency warned that drivers in the Tucson area should anticipate the impact on Wednesday morning commutes on and around I-10.

“This is going to be an extended closure,” he said in a tweet Tuesday night.

The University of Arizona Tech Park was among the evacuated areas. Several schoolchildren from Rita Ranch were among those who took refuge there. Arizona Daily Star reportedAuthorities canceled classes at several nearby schools on Wednesday.

What is nitric acid?

Nitric acid is used in the production of ammonium nitrate for fertilizers and in the production of plastics and dyes.

According to the Centers for Disease Control and Prevention website, nitric acid is a highly corrosive, colorless liquid with yellow or red smoke that can cause a pungent odor.

Exposure to nitric acid can irritate the eyes, skin, and mucous membranes. Depending on how long and how much someone is exposed to the substance, it can cause delayed pulmonary edema, pneumonia, bronchitis, and tooth erosions. There is also

On Wednesday, the Pima County Department of Health and Poison Control Center recommended that anyone who may have been in contact with the gas for more than 15 minutes seek medical evaluation if they develop difficulty breathing, including wheezing or shortness of breath. bottom. They said symptoms could be delayed for up to 24 hours after exposure.

Health officials say some people living within a mile of the accident were exposed to the substance for more than 15 minutes if the building they were sheltering in was using an air conditioner or heater that drew air from outside. However, they said people who had simply driven by or passed through an accident or chemical plume should not have been affected.

The dangerous clash continues to raise concerns about the release of toxic chemicals on a freight train that derailed on Feb. 3, setting 50 cars into flames. It happens sometimes. No one was injured, but authorities later ordered the immediate area evacuated. Residents are concerned about the potential health effects of debris.