CSB Releases Safety Video on Fatal Acetic Acid Release
On July 11, the U.S. Chemical Safety and Hazard Investigation Board (CSB) released a safety video on an acetic acid release that fatally injured two contract workers at the LyondellBasell LaPorte Complex in LaPorte, Texas, on July 27, 2021. Titled “Designed to Fail: Chemical Release at LyondellBasell,” the video features animations depicting the circumstances that led to the incident. Voice-over narration and commentary from CSB Board Member Sylvia Johnson, PhD, and investigator Benjamin Schrader, PE, explain the agency’s findings and safety recommendations to the American Society of Mechanical Engineers (ASME), the American Petroleum Institute (API), and LyondellBasell.
The acetic acid release occurred after three contracted workers employed by Turn2 Specialty Companies inadvertently removed the bolts that secured the cover of a pressure-retaining valve, or actuator, when attempting to repair a leaking pipe. The valve cover and plug ejected, and all three Turn2 workers were sprayed with about 164,000 pounds of acetic acid mixture at a temperature of 238 F. In addition to the two contractors who were killed by chemical burns and inhalation of the mixture, a third contractor and a LyondellBasell employee were seriously injured. Twenty-nine other workers received medical evaluation and treatment.
The CSB safety video outlines two major safety issues that contributed to the incident’s severity. First, the valve was not designed in a way that prevented human error. CSB’s investigation identified four other incidents in which workers were killed or seriously injured after inadvertently removing pressure-retaining components from plug valves during maintenance. According to the safety video narration, “CSB believes that the recurrence of these types of incidents points to the need to redesign plug valves so that it is very difficult to accidentally remove pressure-retaining components.”
Investigator Schrader added that “the best way to address this type of incident would be by prevention through design of new plug valves.” CSB recommends that ASME and API revise their standards to require that all pressure-retaining components be clearly marked on existing plug valves and that new plug valves be designed to prevent the inadvertent removal of these components. In the meantime, Schrader advised employers to use color-coded paint and warning signs to label pressure-retaining components.
The second safety issue was LyondellBasell’s failure to develop a procedure for safely removing plug valve actuators or ensure that contractors were capable of doing the work. “Had LyondellBasell performed a risk assessment to ensure safeguards were in place during the actuator removal,” Schrader said, “as well as provided the Turn2 work crew with written procedures, proper training, and oversight, this incident could have been prevented.”
CSB’s safety video may be viewed on YouTube. More information is available in the agency’s press release about the video and webpage for the July 2021 incident.