In a new video safety message released on YouTube, Chemical Safety Board Chairman John Bresland urged companies to ensure they have effective winterization programs to prevent major chemical and refinery process accidents that could result in deaths or substantial property damage.

“Winter is here,” Chairman Bresland said. “As temperatures continue to drop, it's important for process plants to be prepared for the unique safety challenges of subfreezing weather.”

Chairman Bresland cited two serious accidents investigated by the CSB where water froze inside piping or equipment, causing it to rupture and releasing flammable liquids that ignited.

At a refinery near Dumas, Texas, in February 2007, a water-containing pipe froze and cracked, releasing high-pressure liquid propane; the resulting fire burned three workers and caused more than $50 million in property damage.

In January 2001, two workers burned to death at a large Indiana steel mill after they were sprayed with flammable gas condensate, which ignited. The accident occurred after ice had cracked and damaged a valve in the mill's coke oven gas distribution system.

“Companies should establish formal, written winterization programs, and they should apply appropriate management of change techniques when piping or equipment is taken out of service,” said Bresland in the video.

The accidents in 2001 and 2007 involved what are known as dead legs, or sections of piping that do not have any flow of liquid. The safety message noted that dead legs are particularly susceptible to freezing hazards and should be surveyed and then removed, isolated, or properly winterized.

The CSB is an independent federal agency charged with investigating industrial chemical accidents. The agency's board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management systems.

The Board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA.