People walk to a Harris County Sheriff air boat while escaping a flooded neighborhood. (Brendan Smialowski/AFP/Getty Images)

A chemical plant in Crosby, Tex., was in critical condition Tuesday night after its refrigeration system and inundated backup power generators failed, raising the possibility that the volatile chemicals on the site would explode.

Arkema, a maker of organic peroxides commonly used by the plastics and rubber industries, evacuated all personnel from the plant and was attempting to operate the facility remotely.

The materials must be kept at low temperatures; otherwise they could combust.

An employee at a neighboring company said the chemicals should be kept at a temperature of about 30 degrees.

“The situation at the Crosby site has become serious,” the company said on its Web page. “At this time, while we do not believe there is any imminent danger, the potential for a chemical reaction leading to a fire and/or explosion within the site confines is real.”

Arkema had shut down the plant last Friday, anticipating the storm before Harvey made landfall.

The company said that more than 40 inches of rain had already fallen and the site was “heavily flooded” and without electricity since early Sunday morning. Backup power generation failed too.

The company said it tried to transfer products from warehouses into diesel-powered refrigerated containers, but Tuesday afternoon it decided the danger was great enough to evacuate workers.

The company said it was working with officials from the Department of Homeland Security.

The worker from a neighboring facility, who asked for anonymity because she does not speak for her company, said that if all else fails, the “you get out and try not to be downwind.”

Arkema has plants in half a dozen countries, including 34 in the United States. Five of those, including Crosby, are located in Texas. As of 2015, there were 57 employees at the Crosby plant. The company website says that the chemicals it produces are used in countertops, paints, headlight assemblies, polystyrene cups and plates, and PVC pipes and packaging.

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