Weaknesses in safety management systems and organizational safety culture contributed to the severity of a 2014 incident at a chemical facility in La Porte, Texas, that killed four workers, according to a report by the U.S. Chemical Safety and Hazard Investigation Board.

However, one member of the board also expressed concerns about employee incentive programs in chemical facilities and urged the industry to reconsider such incentives.

In November 2014, about 24,000 pounds of highly toxic methyl mercaptan was released from an insecticide production unit at the E.I. du Pont de Nemours and Co., killing three operators and a shift supervisor, according to the report. They died from a combination of asphyxia and acute exposure by inhalation to the toxic material.

“Our investigation revealed a long chain of failures leading up to the single event, including deferring much-needed process improvements that could have prevented the toxic release,” Kristen Kulinowski, the CSB’s interim executive, said at a hearing in Washington on Tuesday.

The release was caused by the “flawed” engineering design and the lack of adequate safeguards, with numerous safety management system deficiencies contributing to the severity of the incident, including deficiencies in formal process safety culture assessments, auditing and corrective actions, building ventilation design, toxic gas detection and emergency response, according to the report.

“Weaknesses in the DuPont La Porte safety management systems resulted from a culture at the facility that did not effectively support strong process safety performance,” the report stated. “The highly toxic methyl mercaptan release resulted from a long chain of process safety management system implementation failures stemming from ineffective implementation of the process safety management system at the DuPont, La Porte facility.”

DuPont created a corporate process safety management system that integrated its internal safety requirements with those of the American Chemistry Council’s Responsible Care program and those required by regulations under the U.S. Environmental Protection Agency’s Risk Management Program and the U.S. Occupational Safety and Health Administration’s process safety management standard, but still experienced three major process safety incidents over the course of five years, according to the report.

The CSB also identified significant process safety deficiencies at the DuPont La Porte site that contributed to the incident. “DuPont’s corporate process safety management system did not identify, prevent, or mitigate these deficiencies,” the report stated.

The CSB’s final report showed that this was “a tragic incident that didn’t have to end the way it ended,” said CSB Board member Manuel Ehrlich said. “When I came out of school in the ’60s, DuPont was the gold standard in the chemical industry, and unfortunately they did not put the emphasis on culture improvement and process safety and issues other than revenue generation, and that led to” the fatal incident.

The CSB also identified issues in the emergency response to the fatal incident. “The emergency response efforts at the DuPont La Porte facility during the toxic chemical release were disorganized and placed at risk operators, emergency responders and potentially the public,” the report stated. “Chemical plants need a robust emergency response program to mitigate emergencies and to protect the health of workers, emergency responders and the public.”

An emailed statement from the company on Tuesday expressed its “deepest sympathies” for the friends and families of the deceased workers.

“We are committed to maintaining a safe working environment at our facilities and will work to continuously improve our safety systems,” the company stated. “From the time that the Chemical Safety Board (CSB) first deployed to the site in the days after the incident and throughout the agency’s investigation, E.I. du Pont cooperated completely. Although we disagree with some of the agency’s findings, we value the CSB’s perspective and will carefully consider the recommendations directed to E.I. du Pont.”

Board member Rick Engler voted for the report but also submitted a dissenting statement related to his concerns that DuPont La Porte’s bonus structure may have disincentivized workers from reporting injuries, incidents and near misses, according to the report. The facility implemented a variable compensation, or bonus, system that did not use process safety management performance metrics. Instead, it used a safety modifier based solely on OSHA total recordable injuries and it was constructed in a way that could have potentially disincentivized reporting injuries, the CSB determined.

“Although we did not find that the employee incentive system on-site, which essentially only increased compensation as a result of lower recordable injuries, was a causal factor, there was a careful evaluation done of this matter … and I think it offers a valuable lesson to the industry,” Mr. Engler said. “I would add that the very existence of an incentive system that pays people based solely on a metric around reduced injury and illness rates immediately raises a question about (whether) the organizational, for lack of a better term, culture at the facility is one that should be investigated.”

The CSB did not issue a recommendation on this issue because of the lack of a causal connection and the fact that there are thousands of facilities in the United States, and if it had issued a recommendation, that would raise practical concerns about how the CSB would track whether these facilities had such programs, Mr. Engler said.

The CSB did not issue recommendations to OSHA specific to the DuPont La Porte report, but earlier this month suggested OSHA develop effective oversight that addresses the unique hazards of the onshore drilling industry in the wake of a blowout that fatally injured five workers at the Pryor Trust gas well in Oklahoma last year.

Meanwhile, CSB’s investigative team on Monday arrived on the site of a Philadelphia refinery explosion and fire that occurred on Friday and has seven other investigations in various stages of development as well as draft reports under review, Ms. Kulinowski said.

The CSB has been threatened with elimination on multiple occasions and currently has only eight investigators. The U.S. House of Representatives recently approved its $12 million budget request for fiscal year 2020. While the U.S. Senate has not begun moving 2020 fiscal bills, the board is hopeful that it too will support the budget request, Mr. Engler said.

The CSB’s budget is “is way too low,” said Michael Wright, director of health, safety and environment for the United Steelworkers in Pittsburgh.

But many stakeholders objected to the CSB’s decision not to include dedication pages to the deceased employees in either the Pryor or DuPont LaPorte reports — a break from previous reports and recommendation documents — and urged the board to reconsider. Board members were split on this issue, with Mr. Engler not supporting the removal of the names and ages of the individuals who were killed from the report and Mr. Ehrlich saying he was not in favor of an identification page in CSB reports.

Ms. Kulinowski said she has directed the CSB’s general counsel to examine the issue and recommend a course of action informed by laws, regulations other federal government agency policies where there is an investigative and public reporting component and other relevant information.

“We understand that there is a lot of passion around the subject,” she said. “We at the CSB share the passion that you do about safety, and we dedicate ourselves every day to preventing chemical incidents, through our investigations, so that workers are not killed on the job.”