You'd have a little more respect for the potential dangers of working with acetylene if you'd been in Dallas on July 25, 2007. At nine thirty in the morning that day, Southwest Industrial Gases went up in an exploding fireball. Opinions vary as to the cause of the accident- valve failure, misuse of a practice called "pigtailing," or negligence. The company supplying Southwest with acetylene at that time (Western International Gas & Cylinders), according to STEVE THOMPSON, MICHAEL GRABELL and RANDY LEE LOFTIS of The Dallas Morning News, "...has won industry safety awards. But federal regulators have repeatedly cited it for safety violations."
Here are a few points courtesy of the Bureau of Deep Mine Safety:
-Acetylene is a compound of Hydrogen and Carbon (C 2 H 2 )
-Explosive range is 3% -93%
-Needs only 10% oxygen to ignite
-Produced when calcium carbide is mixed with water
-Unstable gas, will violently decompose when pure state above 15 psi
-Has a burning temperature of 4,600 degrees F when burned in air, and 5,700 degrees F when burned in pure oxygen
-Auto-ignition temperature is 763 - 824 degrees F
-Usually are steel construction
-Filled with a porous material to allow the acetylene to dissolve - -Comes in various sizes
-Must always be stored upright
-Should not be stored below freezing
-Never allow a tank to go empty
What is interesting to me now about acetylene and other stored compressed gas issues is not so much the mechanisms of ignition and other catastrophic events, it is that responders are called to respond to emergency situations where compressed gases are stored. I wonder if they are fully aware of what they're getting into.
Many years ago I was visiting a compressed gas production facility when a fire broke out. The fire department was called to put out the fire. People in the facility, including myself, were herded outside to the far edge of the park lot. When the fire truck pulled in, I watched it make a beeline for the plant, then suddenly turn around and drive away from the building. The driver had apparently noticed the "Acetylene Production" sign.
I was told recently by a friend involved with emergency response that fire departments regularly review Tier II filings from the companies in the areas to get a heads up on what hazardous chemicals are stored at their facilities so that there are no surpises.
To further explore how this works over the next week, I will be contacting and reporting on interviews with two experts. The first is Dennis Patrick, President of the Environmental Planning Group out of Ashley, MI. Mr. Patrick is a CIH, CHHM, and CSP. He is also a compressed gas industry professional with over thirty years of operational and management experience. A special area of expertise for him is Tier II filings and RMP plans. I'll ask him just how helpful the information contained on the Tier II forms required by EPA can be to Emergency Responders. Second, I'll be talking to a well respected local Fire Chief to ask him for his take on this as soon as he gives me his permission to publish the interview.
See you Thursday. And by the way, the picture below shows why not to transport acetylene in a car.