The Houston area is on edge over uncertainty about a nearby chemical plant compromised by Hurricane Harvey’s disastrous flooding, as a company official today declined to say definitively that the smoke emanating from burning substances on the site is nontoxic.

Authorities first notified Arkema Inc., which runs the plant, at around 2 a.m. CT today about a pair of apparent explosions heard and plumes of black smoke seen rising from the facility in Crosby, Texas, which produces organic peroxides used in a variety of products, including construction material.

At a news conference later this morning, Arkema executive Richard Rennard said the smoke and loud “popping” noises came from one of nine containers on site holding liquid organic peroxides that must remain cold, or the chemicals will become unstable and will start to break down as they warm up.

The plant lost its ability to keep the product refrigerated because of to the storm’s floodwaters and power loss.

“When they decompose, they will generate heat; and when they generate heat, there’s a possibility of a fire and an explosion,” Rennard told reporters. “This is a very serious issue and we know that.”

Rennard said officials of the French company don’t believe an explosion has occurred at the plant yet, but that the “popping” is the sound of pressure building up inside the container, exceeding the safety valve and then being released.

“We believe it’s just been these vapor relief valves that have been popped,” he told reporters. “Certainly, these things can burn very quickly and very violently, and it would not be unusual for them to explode.”

Arkema anticipates the same product stored in the other eight containers will also degrade and combust; it’s just a question of when.

“We totally expect the other containers will start to do the same thing,” Rennard said. “Whether it’s today, tomorrow, we just don’t know. … It’s not over.”

Rennard assured reporters that the containers were situated in a “remote area” of the chemical plant and that Arkema doesn’t anticipate any other areas or buildings to be affected.

The smoke coming from the container will irritate the eyes, lungs and potentially skin, according to Rennard. Arkema encourages anyone who has been exposed to the smoke to contact their doctor or seek medical advice, Rennard said.

The Harris County Fire Marshal’s Office has urged residents within a 1.5-mile radius of the facility, which is about 27 miles east of Houston, to evacuate the area.

The Harris County Sheriff’s Office said on Twitter that 15 deputies “complaining of respiratory irritation” after monitoring the “incident” at the Arkema plant were taken to the hospital. All are “healthy and have been released, the sheriff’s office said.

At this morning’s news conference, Harris County Sheriff Ed Gonzalez likened the smoke emanating from the facility to “standing over a barbecue pit or something like that, when you get smoke in your eyes.”

Arkema initially said it believes the smoke inhaled by the officers is a “non-toxic irritant.” But when pressed repeatedly by reporters this morning on whether the fumes are definitely not toxic, Rennard wouldn’t say.

“The smoke is certainly noxious,” Rennard concluded, defined as harmful and capable of causing injury.

But toxicity is “a relative thing,” he told reporters, citing the fire’s apparent absence of plant chemicals. Continue reading.