More robust guidance is needed to help hazardous chemical facilities prepare for extreme weather events, according to the U.S. Chemical Safety and Hazard Investigation Board.

Hurricane Harvey dropped an unprecedented amount of rain on King of Prussia, Pennsylvania-based Arkema Inc.’s Crosby, Texas, facility, causing equipment to flood and fail and stored chemicals to decompose and burn, releasing fumes and smoke into the air, according to the board’s final investigation report into the Aug. 31 fire at the facility.

Arkema, which has a history of workplace safety violations, evacuated all of its employees and more than 200 residents living nearby, with 21 people seeking medical attention from reported exposures to the airborne fumes and smoke. 

The Arkema chemical plant manufactures and distributes organic peroxides — some of which must be kept below 32 degrees Fahrenheit to prevent them from decomposing and catching fire, according to the CSB’s statement.

Under normal operation, the organic peroxides are stored in low-temperature warehouses and shipped in refrigerated trailers. However, extensive flooding caused by heavy rainfall from Harvey caused the plant to lose primary and backup power to all of the low-temperature warehouses. Workers at the Arkema facility moved the organic peroxides to the refrigerated trailers, which were then relocated to higher elevations. But three of the trailers couldn’t be moved and eventually flooded and failed. With refrigeration on those trailers lost, there was nothing to stop the chemicals inside from heating up and catching fire, according to the statement.

The CSB made specific recommendations for the company to “reduce flood risk to as low as reasonably practicable” and ensure that any safeguards for flooding meet independent layers of protection requirements, according to the report.

Arkema should also develop a policy requiring units that manufacture organic peroxides or that have processes which involve more than the threshold quantities of highly hazardous chemicals to periodically analyze such facilities to determine whether they are at risk for extreme weather events such as hurricanes or floods. The company should also establish corporate requirements to ensure that critical safeguards, such as backup power, function as intended at these facilities during extreme weather events, according to the board.

An Arkema spokesperson could not be immediately reached for comment on the report.

The CSB also reiterated recommendations that the U.S. Environmental Protection Agency revise its Risk Management Plan program to “explicitly cover catastrophic reactive hazards that have the potential to seriously impact the public, including those hazards resulting from self-reactive chemicals and combinations of chemicals and process-specific conditions.” The EPA last week announced its intention to rescind planned changes to the RMP program designed to prevent catastrophic incidents such as the West, Texas, fertilizer disaster that killed 15 people.

Guidance on addressing flood hazards at chemical facilities was previously available from several different sources, including the New York-based Center for Chemical Process Safety and the Federal Emergency Management Agency, according to the report.

“This guidance, however, is either too generic or does not require sufficiently conservative precautions to have helped Arkema prevent this incident,” the report stated. “For example, this guidance does not require elevating critical equipment to heights that would have prevented Hurricane Harvey-level floodwater from disabling safety systems at the Arkema Crosby facility. Given this type of shortcoming, more robust industry guidance is needed to help hazardous chemical facilities better prepare for extreme weather events, such as flooding, hurricanes, snowstorms, tornadoes, or droughts.”

The board recommended that the center provide comprehensive guidance to chemical facilities about mitigating the risk associated with extreme weather events. A center spokesperson could not be immediately reached for comment.

“Our investigation found that there is a significant lack of guidance in planning for flooding or other severe weather events,” Vanessa Allen Sutherland, the CSB chairperson who announced her resignation on Monday, said in a statement on Thursday. “Based on other government reports, we know that there is a greater likelihood of more severe weather across the country. As we prepare for this year’s hurricane season, it is critical that industry better understand the safety hazards posed by extreme weather events.” 

Facilities should perform an analysis to determine susceptibility to potential extreme natural events, according to the board’s recommendations. Companies should evaluate the potential risk of extreme weather events and the adequacy of safeguards when conducting analyses of process hazards or facility siting and should strive to apply a sufficiently conservative risk management approach, the board recommended.

If flooding is the risk, facilities must ensure that critical safeguards and equipment are not susceptible to failure by a common cause and that independent layers of protection are available in the event of high water levels, according to the board.