As the world watches the consumer market grapple with defects found in imported products like pet food, toothpaste, toys and tires, it's easier to understand how the safe performance of industrial products like hot work fabrics — commonly known as fire blankets — also can be greatly diminished in the absence of adequate performance standards and ongoing third-party certification to those standards. This especially is true in this era of globalization with longer, more intricate supply chains.
Hot work operations such as welding and cutting are most critical in heavy industries like oil refining, petrochemicals, power generation and shipbuilding. However, no organization performing hot work is free of risk, as evidenced by the large number of hot work fires listed by the National Fire Protection Association (NFPA). Operations such as food processing plants, universities, hospitals, missile silos and paper mills have all experienced losses due to hot work accidents.
Insurance Claims Pointed to Need for Change
With hot work accident losses mounting, risk management and consulting firm FM Global conducted a study of its clients' losses over a 10-year period. The number was staggering — a total of $750 million, or $1.3 million per incident. This led FM Global to take two specific steps toward lessening the risk of fire during hot work:
Step #1 — Advise clients how to improve their existing hot work safety practices. This included adopting the practice of issuing and auditing hot work permits with specific requirements for all such operations, thereby holding all workers on the job accountable for hot work safety, employees and outside contractors alike.
Step #2 — Develop a performance-based standard for evaluating and rating hot work fabrics, or fire blankets.
Safety Suffered in Absence of Performance-Based Standards
The goal in developing such a performance-based standard is obvious: to end the race to the bottom by suppliers and end-users who are more focused on price than safe performance. As one refinery maintenance supervisor declared, “Fire blanket is expensive!”
Without tight standards, purchases too often are made on subjective criteria — like color of the product — allowing suppliers to offer ever-cheaper alternatives that may be ineffective fire protection products. Making bad choices is not surprising when one understands that the only requirement referenced in most hot work safety standards was (and still is) the use of “heat-resistant tarpaulins” — a tepid recommendation more appropriate for painting than welding. In place of fire-retardant materials, tarps made of plastic, cotton and worse have found their way onto jobsites where fire risk is high.
FM 4950 and ANSI/FM 4950
FM Approvals, the testing and certification arm of FM Global, tackled the challenge of developing the first performance-based standard for welding curtains, blankets and pads. After several years of work, the FM 4950 standard was introduced to FM clients and fire blanket manufacturers in 2002. The standard includes three important components:
- Performance-Based Test Procedures
- Product Labeling Requirements
- Periodic Audits of Manufacturers
In early 2007, the FM 4950 test procedures were adopted by the American National Standards Institute as ANSI/FM 4950. For the first time, safety professionals and their suppliers can be assured that only tested and approved products are being used on the job, regardless of where they are made.
Good Standards Take Time
The scope of the ANSI/FM 4950 standard, as outlined in the standard's documentation, offers some insight into why it took so long for such a standard to be developed and why it took an engineering firm like FM Approvals to create the complex and inter-related test procedures. It details the following testing rationale:
“The fire performance of a fire-resistant cover depends on the type of welding function to which it will be subjected. In general, welding pads, welding blankets and welding curtains are evaluated on their ability to:
Prevent burn through of the material and provide adequate protection for adjacent combustibles from possible sources of ignition;
Limit temperature transmission through the material to a degree that will prevent ignition to underlying combustibles;
Resist melting, dripping or deformation so as to prevent sparks from spreading outside of confined and protected areas;
Maintain their flexibility, durability and structural integrity when charred areas are subject to 90 degree bends;
Maintain their fire and temperature rise resistance properties when subjected to accelerated weathering tests intended to simulate exposure to light and water (ultraviolet and condensation, respectively) conditions.”
Covers Broad Spectrum of Hot Work
In order to replicate such a wide array of real-world industrial applications and achieve certification as welding pads, welding blankets or welding curtains, the standard calls for three test procedures to be conducted.
Fire and Thermal Test — The carefully controlled torch cutting of three-quarter-inch thick steel plate in close proximity to either a horizontally placed fabric specimen (pad or blanket candidate, as defined below) backed by thermocouples and a sheet of paper or a vertically placed fabric (curtain candidates) to contain sparks and slag.
Charring and Embrittlement — After enduring fire and thermal testing, horizontally placed fabrics are bent over a 1-inch pipe and are pulled at right angles in two directions, then inspected for cracking or other openings in the fabric.
Weatherization — Fabrics are then subjected to 1,000 hours (about 42 days) of simulated outdoor conditions such as rain, dew and sunlight.
After weatherization, horizontally placed fabrics are then re-tested to the heat and durability procedures. The full battery of tests spans several months.
The testing is rigorous enough to weed out inappropriate fire blanket materials, but end-users still need to make choices based on the nature of their operation. Now, however, they can make the choice from a “good, better, best” list instead of taking a chance with a “bad or worse” choice.
Utilizing ANSI/FM 4950
The ANSI/FM4950 standard confirms that fabrics are an important part of a fire prevention system, as are the safe hot work practices detailed in standards like NFPA 51B. Such standards will be updated to include fabric test requirements, but safety professionals can begin putting the standard to work now by downloading ANSI/FM 4950 from the FM Global Web site (http://www.fmglobal.com/approvals/resources/standards.asp).
Safety professionals also should review current hot work operations and compare to rating designations as defined in the standard. Such an exercise will help determine if a re-evaluation of acceptable fabric choices is appropriate. Update the hot work policy to specify only “tested and approved” hot work fabrics be used on the job. This simple change will assure that all suppliers are compliant with ongoing certification requirements.
Don't Take Risks
Holding suppliers' feet to the fire on safety-related products like fire blankets has never been more important, given the uncertainties of today's supply chains. Suppliers and end-users alike are at risk if a product purchased on an ongoing basis has not been produced by a company that is subject to ongoing certification rather than a one-time approval process. Third-party certification is absolutely critical to safe product performance.
When an insurer like FM Global drives the development of a performance standard and ANSI adopts it, suppliers are wise to embrace it or be ready to suffer the losses associated with ignoring it. By adopting this hot work fabric standard, participants all along the supply chain can optimize safety and efficiency in their operations.
Kathie M. Leonard is president/CEO of Auburn Manufacturing Inc., a leader in extreme-temperature solutions for industry. Currently, 17 of Auburn Manufacturing's hot work fabrics have been tested and approved to ANSI/FM 4950.
Welding Curtain — Primarily vertical applications with light to moderate exposures to sparks and heat. Designed to prevent sparks from escaping the designated work area.
Welding Blanket — Horizontal applications with light-to-moderate exposures to molten metal slag. Designed to protect machinery and prevent ignition of combustibles in designated work area.
Welding Pad — Horizontal applications with severe exposures, such as that resulting from molten substances. Designed to prevent the ignition of combustibles located under the pad.