US environmental regulators are investigating whether the Arkema chemical plant in Texas followed safety rules ahead of explosions last month caused by flooding from Hurricane Harvey, according to media reports.

The Environmental Protection Agency has asked the company whether it followed risk management plans submitted to the government ahead of the explosions at the plant, which began on August 31, EPA Administrator Scott Pruitt told the Washington Examiner.

Unprecedented flooding from Hurricane Harvey, which made landfall in southeast Texas on August 26, cut power and knocked out backup generators at the plant -- disabling the refrigeration required to prevent volatile organic peroxides from exploding.

Authorities had already evacuated an area within a 1.5 mile (2.4 kilometer) radius of the plant. But emergency workers who responded to the explosions have since sued the plant's operators for exposing them to smoke.

"There is some question about whether the RMP that was in place was actually complied with," Pruitt told Washington Examiner, referring to a risk management plan. The September 7 letter gave Arkema 10 days to answer to EPA queries.

The EPA wants to determine what quantity of chemical substances were stored at the plant and what safety measures had been taken in advance of possible flooding and power loss.

The company told AFP on Tuesday its "first priority" was the safety of the public and employees.

Arkema is responding to multiple government investigations -- including one by the Chemical Safety Board, a different government regulator -- but Arkema could not confirm having received the EPA letter, according to a company spokesman.

"When those investigations are concluded, we will all have the benefit of a detailed examination of what happened," the spokesman said.

The company also expects additional litigation but believes the lawsuit brought in Texas by first responders is without merit.

"While we appreciate the service of the many first responders who worked with us side-by-side to keep the public safe, we will vigorously defend a lawsuit that we believe is gravely mistaken," the spokesman said.

Source: AFP