Cold weather is dangerous for a number of reasons. For workers at chemical plants, it brings significant risks that plant owners and operators must address to avoid catastrophic accidents like spills, fires, and explosions. Winterization, the process of readying a plant for cold temperatures, is necessary to prevent weather-related incidents. If winterization is delayed or carried out improperly, however, every worker at a plant may be in danger. The situation can be even worse when chemical plant owners avoid winterization altogether.
How Cold Temperatures Impact Chemical Plants
No matter where you live in the United States, you may have noticed that winters seem to be harsher, summers longer, and storms worse. According to the EPA, studies indicate that human-induced climate change may lead to more extreme weather events, including both heat waves and extreme winter storms.
One of the most recent examples of extreme winter weather occurred in Texas in February 2021. Referred to as the Winter Outbreak by the National Weather Service, a strong Arctic cold front passed through southeast Texas. Snow and sleet fell across the state. Temperatures dropped down to a mere 5° Fahrenheit in College Station, 13° in Houston, and 20° in Galveston. Widespread power outages lasted for days, leaving millions of Texans freezing and in the dark. The Department of State Health attributed 246 deaths across 77 counties to what was one of the worst natural disasters in Texas history.
Chemical plants must focus on proper winterization now more than ever before.
When temperatures drop, water and other materials at chemical plants may freeze. When they freeze, they expand. When they expand, they can cause significant damage. Pipes may crack or break, process equipment may be damaged, and instrumentation may fail. Sometimes this damage is not evident until temperatures begin to rise again. As the ice thaws, leaks can develop. These leaks may go undetected until there is a serious problem. Cold temperatures can also cause solid hydrates to form in piping, which can create blockages that lead to deadly accidents.
DuPont Chemical Plant Accident in LaPorte, TX (2014)
In November 2014, 4 workers lost their lives as a result of a toxic chemical release at a DuPont pesticide plant in LaPorte, Texas. Days before the deadly incident, water had mixed with liquid methyl mercaptan in outdoor piping. Because the pipes were not properly protected from the cold, low temperatures caused the mixture to form a solid hydrate, blocking the piping.
Upon discovering the blockage, a DuPont company team drafted a plan. They would spray hot water on the piping to melt the hydrate while opening valves from the affected pipe into a vent piping system to prevent problems caused by thermal expansion. Workers labored through the night, pausing to take a break after their initial attempt to clear the blockage failed. It was during this break that a new issue arose: there was too much pressure in the vent piping system.
The vent piping system at the LaPorte plant had been experiencing issues for some time. Every day, workers had to go inside the manufacturing building to drain liquid from the vent piping system. On the night of the accident, two workers went to the manufacturing building to do this, not realizing that the blockage had been cleared and that liquid methyl mercaptan was now draining from the open valves. The room was filled with toxic vapor. One of the workers called for help, and two workers responded to the distress call. All four workers lost their lives.
This is just one tragic example of how a company’s failure to winterize a chemical plant led to a deadly accident. Refineries, plants, and other facilities that contain hazardous materials must be properly winterized to avoid catastrophic injuries and losses of life.
What Is Winterization?
Winterization is a term used to describe the process that a plant, refinery, or other facility undergoes to prepare for cold weather. Depending on the type of facility and the anticipated temperature drops, winterization may include a number of plans, processes, and procedures. Ideally, winter preparations should begin in the late summer or early fall, giving ample time to identify and fix any potential problems or deficiencies.
Winterizing a chemical plant may include such steps as:
- Retrofitting piping, instruments, and equipment for cold weather
- Putting up wind barriers
- Increased monitoring of critical areas
- Inspecting and upgrading equipment to better withstand cold temperatures
- Increased frequency of operator rounds during winter months
- Training workers on winterization methods and best practices
- Educating workers on how to recognize potential problems
- Drafting plans on how to address weather-related problems
- Completing a full walkthrough of the entire facility when winterization is complete
Plant operators should create winterization checklists that include every single step to prepare a facility for cold weather. A formal winterization program, in writing, can help ensure nothing is missed. The program should also include best practices for returning a plant to normal operations when cold weather has passed.
Winterization Regulations & Best Practices
According to the U.S. Chemical Safety and Hazard Investigation Board (CSB), chemical plant owners and operators should implement policies and procedures that address low temperatures and their impact on piping, equipment, and instrumentation. These procedures should reflect a year-round focus on cold weather preparation, including winterization and returning a plant to normal operations as temperatures rise again.
Detailed information and insight can be found in the CSB’s Safety Digest: Preparing Equipment and Instrumentation for Cold Weather Operations.
A Winter Weather Wake-Up Call for Chemical Plants
In February 2022, the U.S. Government Accountability Office (GOA) issued a report detailing the risks climate change may present to regulated facilities like chemical plants. According to the report, about 31% of facilities that make, use, or store hazardous chemicals are located in areas of the United States where natural disasters like floods and severe storms are known to strike. Many believe that natural disasters will only worsen in intensity and frequency along with climate change. Texas is proof of that.
Chemical plants must not ignore extreme winter temperatures, particularly considering the risks that hazardous chemicals can present to the environment, plant workers, and entire communities. The GAO has called for enhanced measures to assess the risks of severe weather events and natural disasters, track compliance and deficiencies, and enforce appropriate risk management programs. These measures are meant to reduce the risk of a chemical release or other catastrophe caused by extreme weather.
Too often, workers are often the ones who pay the price when companies cut corners by delaying winterization or failing to replace aging or defective equipment. Sometimes, like the four workers at the DuPont plant in LaPorte, they pay with their lives. Improper winterization can also increase the risk of a spill that affects groundwater and delicate ecosystems, not to mention local communities, wildlife, crops, and cattle.
Winterization is not optional for chemical plants in areas where temperatures drop to dangerous lows. Companies owe it to their workers, the communities where their plants are located, and the environment to take the appropriate measures that prevent weather-related incidents.