The Crosby, Texas, site of French chemical producer Arkema’s US subsidiary was inadequately prepared for the flood that inundated it during Hurricane Harvey last year, the Chemical Safety Board (CSB) has reported. Arkema sees itself vindicated by the CSB’s findings, as they "accurately depicted the unforeseeable nature” of the flooding.

An investigation by the CSB found that the company’s plant near Houston, despite having a written hurricane preparedness plan, relied on the judgment of its employees rather than official flood insurance maps to determine the amount of risk. Arkema’s safety procedures in place for extreme weather “proved no match for the historic floods,” the safety board said.

"Employees with decades of plant experience expected only light flooding at the facility, but not enough to impair any safety systems," the report said. Workers moved volatile organic peroxides to cold storage trailers; however, these, too, were soon covered by 1.8 meters of water. Some of the trailers failed, causing chemicals inside to overheat and ignite.

During the blaze, hundreds of residents within a 1.5-mile radius of the facility were evacuated for a week, and nearly two dozen received medical treatment for exposure to fumes and smoke.

The company sees itself vindicated by the CSB’s findings, as the board "accurately depicted the unforeseeable nature" of Hurricane Harvey's flooding. "If the floodwaters had only reached a 500-year flood level, the incident likely would have been prevented based on Arkema's existing policies and procedures," it added.

Apart from Arkema’s facility, the safety board said chemical plants across the US have not received adequate guidance for dealing with major floods, in part because the regulations do not specifically identify flood insurance maps and related studies.

"Considering that extreme weather events are likely to increase in number and severity, the chemical industry must be prepared for worst case scenarios at their facilities," CSB Chairwoman Vanessa Sutherland said.

Along with Exxon Mobil’s Baytown, Texas, site, Arkema’s Crosby facility was ranked among the Houston-area sites with the highest potential for harm in an incident, according to a 2016 analysis by the O'Connor Process Safety Center and the newspaper Houston Chronicle.

Arkema had previously been fined for safety violations at Crosby, according to reports. Following the 2017 incident, the company was hit with lawsuits from seven rescue workers seeking total compensation of $1 million. The site’s neighbors have sued for personal injury, homeowners are suing over contamination in their neighborhood and two counties, Harris and Liberty, have also filed lawsuits. As yet, no judgments or out-of-court settlements have been reported.