Recently the U.S. Chemical Safety Board (CSB) released a Safety Digest on Startups and Shutdowns that highlights three incidents that occurred during a startup or shutdown, and provides lessons learned that can be used to prevent future startup and shutdown incidents.
Process unit startups and shutdowns are much more hazardous than normal oil refinery or chemical facility operations, the CSB says. A startup is a planned series of steps to take a process from an idle state to normal operation. A shutdown is the reverse sequence.
According to the Center for Chemical Process Safety (CCPS), a majority of process safety incidents occur during a plant startup, even though it represents only a small portion of the operating life of a plant. Process safety incidents occur five times more often during startup than during normal operations, CCPS says. In addition, a 2010 study of incidents in the chemical refining industry showed that more than 50% of process safety incidents occur during startups, shutdowns, and other infrequent events because startup and shutdown periods involve many non-routine procedures, and can result in unexpected and unusual situations.
The CSB says that effective process safety management (PSM) could have prevented the three incidents highlighted in its Safety Digest. One of the recommendations consists of implementing written operating procedures for startup following an emergency shutdown. Some of the topics covered by the written procedures include:
The CSB also stresses that written operating procedures must have enough details to avoid the likelihood of valve misalignments during startups and shutdowns. Written checklists and diagrams to verify proper valve positioning should be provided, if needed.
Finally, organisations can enable effective process safety management through a PSM software solution that includes applications for all 14 elements of OSHA’s PSM standard on a single, integrated platform.