A chemical reaction spawned a fire in a university laboratory last week, the second such explosion within the past month.

Several graduate students were mixing sodium chloride — a highly flammable chemical known to react violently with water — on the third floor of the Chemistry building Thursday when the explosion happened. No injuries were reported.

Four fire stations responded in addition to the Department of Environmental Safety and hazardous materials crews.

University Police Capt. John Brandt said the students were using the chemical inside a closed container.

“When they opened the container, it flared up, so they slammed it shut and got out of there,” he said.

Brandt said his officers moved quickly to evacuate the entire building and closed surrounding roads because it was unclear how dangerous the chemicals were.

On June 13, an accidental chemical explosion sent one student to the hospital with burns suffered on his face and hands.

“You never know with something like that, when it’s reactive chemicals,” he said.

CORRECTION: Due to an editing error, this Diamondback story, “Chemical reaction causes small explosion,” incorrectly states that the chemical that exploded in the Chemistry Building was sodium chloride, which is common table salt. In fact, the chemical was sodium hydride, which is highly flammable when it comes in contact with water. The bank headline, “Second spill within month clears Chemisty Building,” is also incorrect. It wasn’t a chemical spill, but was a fire. The Diamondback regrets these errors.