Handling Hot Work Hazards

The risks associated with performing hot work in a biodiesel facility are many. Fires and explosions caused by sparks from lit torches are, unfortunately, not uncommon. Each incident has its own string of causes and effects, but every loss caused by hot work is 100 percent preventable.
By Kris Bevill | September 16, 2008
Imagine the following scenario: one in a series of four fuel storage tanks needs a pipe to connect it to the next closest tank. All four storage tanks are emptied. A welder is called in to perform the hot work necessary to connect the tanks. After checking for flammable vapors by "flashing" his torch into the empty tank, he and two plant employees climb to the top of the 15-foot tall outdoor tank. The plant employees stand on a ladder leaning on tank two and use makeshift scaffolding, which they brace for the welder so he can cross over to the first tank to begin welding. The welder attaches his safety harness to the top of the tank, lowers himself into position and begins to weld a pipe fitting onto the tank that he will connect by a short pipe to the open-ended pipe on tank two. The instant the welder lights his torch, flammable vapors leaking from the open-ended pipe ignite. The fire flashes back through the series of tanks. The pressure causes the tops of tanks two and three to explode, resulting in the deaths of the two workers who were standing on top of tank two.

The welder, who was attached by safety harness to tank one, was injured but escaped death because the harness prevented him from falling to the ground.

While this scenario is an extreme example of hot work gone wrong, it's a true story. This tragic incident occurred in 2006 at the Partridge-Raleigh oil field in Raleigh, Mo. The details of the explosion are now used as an example of "what not to do" by the U.S. Chemical Safety Board, the independent federal agency whose purpose is to investigate industrial chemical accidents. (A re-enactment of the situation can be viewed at the CSB website: www.chemsafety.gov).
Although this particular incident occurred at an oil field, hot work hazards are similar at any facility that uses flammable chemicals, including biodiesel production plants.



Formulate a Plan
Founded in 1835, FM Global is one of the largest commercial and industrial property insurers in the world. The firm specializes in providing scientific-based risk management solutions for its customers. The company operates the world's largest fire test facility of its kind on the FM Global Research Campus in West Glocester, R.I. At the fire technology lab, research is continuously conducted to better understand the nature and cause of fire, how it behaves and what protection measures FM Global can recommend to its clients.

The mutual company has been insuring chemical companies since at least WWII, according to David Seaman, FM Global's chemical operations vice president and operations engineering manager. He says they have determined hot work to be a "very significant" potential fire hazard at any chemical plant, including biodiesel production facilities and rank it among the top three most common causes of fires at its clients' facilities. "The unfortunate thing is that it can be prevented," he says. "All hot work losses can be prevented by having a proper program in place that's supported by management, and by auditing it annually."

FM Global defines hot work as any temporary or permanent operation that involves open flames or produces heat and/or sparks. This includes but is not limited to: brazing, cutting, grinding, soldering, torch applied roofing and welding.

The obvious risk associated with conducting hot work in any facility is that an ignition source is being used within the confines of an enclosed space. Sparks caused by hot work can combust with chemical vapors resulting in fires that could cause property loss and human loss. The first and most important question for plant managers to ask is: "Is there an alternative to conducting hot work?" If it is possible to remove the piece of equipment that needs to be welded so that repairs can be done in a welding shop then that should be done. Other examples may include:

bolting instead of welding
using hydraulic shears or a reciprocal saw, rather than torch or radial-saw cutting
using fasteners in place of welding
using threaded final pipe or tube connections versus torch-soldered joints
installing a roof-covering system that is not torch applied
hand filing instead of mechanical grinding

In instances where hot work must be conducted on location, the following list of precautions is recommended by FM Global to aid in fire prevention:
Ensure sprinkler systems and other fire prevention systems are fully operable.

Make sure there are fire extinguishers and other manual firefighting tools in the area where the hot work is being conducted.

Ensure hot work equipment is working properly.

Move all combustible material 35 feet away from the area where hot work will be conducted. If that's not possible, cover those materials with welding blankets and screens.

Eliminate explosive atmospheres, i.e. dust and vapors, prior to conducting hot work by shutting down all processes that produce such atmospheres. Continuously monitor the area for combustible gases before, during and after hot work.

Shut down ducts or conveyors that could possibly carry sparks to other combustible areas ofthe plant.

Schedule hot work when the plant is not operational.

Assign a designated fire watch when conducting hot work.

While the list of FM Global's planned precautionary steps is a long one, Seaman says that most chemical plant managers and staff adhere to those steps because they understand the volatility of the situation and take it seriously. In plants that follow FM Global's complete process safety management program, zero losses due to hot work have occurred.

That's pretty convincing evidence that should prompt plants to take a few extra steps to prevent losses. As Seaman says, loss due to fire is not simply a loss of property. A company that experiences an explosion or fire also has to deal with loss of image/reputation, stock price, customers and revenue, not to mention the unfortunate possibility that lives could also be lost as the result of an accident. The added cost and time associated with adhering to a list of precautions is negligible compared with the potential loss due to a fire/explosion, Seaman says. "The key is that it doesn't take that much more time to do it right," he says.

The U.S. Department of Labor's Occupational Safety and Health Administration requires that a process safety management program be in place in any facility that deals with hazardous chemicals. OSHA's regulations for fire prevention are not quite as extensive as FM Global's, but it covers the same basics. OSHA regulations focus more on the ongoing safety of the workers. Its No. 1 recommendation, as it is with FM Global, is to remove the piece of equipment to a welding facility whenever possible rather than repair the piece on site.

Practice What You Preach
FM Global's standpoint is that proper safety management starts at the top, Seaman says. It is up to management to put a comprehensive plan into place and to make sure that plan is adhered to. The key is to have a safety culture instilled into everyone at the site, as opposed to just having a program down on paper. "A program is only as good as the people who are executing it," he says.

Employees should be made aware of the policies and procedural requirements they are expected to follow. Posting a list of policies and procedures where it can be easily seen is one simple way of getting the point across.

Proper training is a responsibility that also falls on management. Seaman suggests ongoing training through an annual certification program for employees involved with hot work.

Of course, not all hot work conducted is performed by plant employees. Contractors are responsible for about half of all hot work done in plants. When working with contractors, once again, communication, training and follow-through is everything, Seaman says. Managers should make sure the contractor knows what type of situation he/she is entering into. Explain the facility's hot work policies, procedures and responsibilities. Educate them "so that when they go in there they know they are dealing with something that has a low flashpoint versus no flashpoint," he says. Have the contractor sign a hot work permit, and then follow-through by dismissing any contractor that doesn't completely follow the plant's precautions and procedures. Work with contractors that have a proven track record and do not allow them to work unsupervised. Also, the employee assigned to the supervisory role must be responsible for the contractor's actions and be allowed to stop the work whenever that person feels it has become dangerous.

Painful Learning Curve
FM Global has found that most plants where losses have been incurred don't have a complete process safety management program, Seaman says. "Most plants have programs," he says. "The question is: How good are they? Is the plan comprehensive enough? Does it deal with all the potentials?" For example, a plant's plan may require a fire watch after hot work has been conducted. But the fire watch might only be required to last for one hour following the work, rather than the full four hours recommended by FM Global.

In the case of biodiesel production plants, the most hazardous place in the facility, when it comes to conducting hot work, is any area where methanol is used. This highly combustible material must be handled with caution. Experienced chemical plant managers know this, of course, but in a new industry such as the biodiesel industry, experienced personnel may not be in charge.

Seaman says that so far the biodiesel industry has proven to be a profitable industry with not many of losses. However, he adds, "the number of losses haven't been significant, but the incidents we're seeing are occurring in the first couple of years of a plant's existence." These "infant mortality losses" are expected in any new industry and can be directly attributed to management practices, he says. "Initially there may have been some new technologies that weren't necessarily approved on certain types of equipment [and there were] operators that were going from one site to the next due to better job offers. That's typical of any new business. You tend to have problems up front, usually because not all the problems were understood up front. If you take the time to understand the potential hazards at the start of a venture, you can then take the necessary steps to reduce the risk of any interruption to your business."

Kris Bevill is a Biodiesel Magazine staff writer. Reach her at kbevill@bbiinternational.com or (701) 373-8044.
 
 
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