What are flame retardants?
What are the most common elements in flame retardants?
How do flame retardants work?
What types of products use flame retardants?
Why are flame retardants important to use?
Are all flame retardants the same?
Q: What are flame retardants?
A: Flame retardants are a key component in reducing the devastating impact of fires on people, property and the environment. They are added to or treat potentially flammable materials, including textiles and plastics. The term “flame retardant” refers to a function, not a family of chemicals. A variety of different chemicals, with different properties and structures, act as flame retardants and these chemicals are often combined for effectiveness.
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Q: What are the most common elements in flame retardants?
A: Bromine, phosphorus, nitrogen and chlorine are commonly used in flame retardants. Inorganic compounds are also used in flame retardants, either alone or as part of a flame retardant system in conjunction with bromine, phosphorus or nitrogen. It is important to note that flame retardants are not readily interchangeable. Their areas of application are often specific and substitution can be difficult.
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Q: How do flame retardants work?
A: Flame retardants are added to different materials or applied as a treatment to materials (e.g., textiles, plastics) to prevent fires from starting, limit the spread of fire and minimize fire damage. Some flame retardants work effectively on their own; others act as “synergists” to increase the fire protective benefits of other flame retardants. A variety of flame retardants is necessary because materials that need to be made fire-resistant are very different in their physical nature and chemical composition, so they behave differently during combustion. The elements in flame retardants also react differently with fire. As a result, flame retardants have to be matched appropriately to each type of material. Flame retardants work to stop or delay fire, but, depending on their chemical makeup, they interact at different stages of the fire cycle. To better understand how flame retardants work, it’s helpful to understand the fire cycle:
- Initial ignition source can be any energy source (e.g., heat, incandescent material, a small flame).
- Ignition source causes the material to burn and decompose (pyrolysis), releasing flammable gases.
- If solid materials do not break down into gases, they remain in a condensed phase. During this phase, they will slowly smolder and, often, self-extinguish, especially if they “char,” meaning the material creates a carbonated barrier between the flame and the underlying material.
- In the gas phase, flammable gases released from the material are mixed with oxygen from the air. In the combustion zone, or the burning phase, fuel, oxygen and free radicals combine to create chemical reactions that cause visible flames to appear. The fire then becomes self-sustaining because, as it continues to burn the material, more flammable gases are released, feeding the combustion process.
When flame retardants are present in the material, they can act in three key ways to stop the burning process. They may work to:
- Disrupt the combustion stage of a fire cycle, including avoiding or delaying “flashover,” or the burst of flames that engulfs a room and makes it much more difficult to escape.
- Limit the process of decomposition by physically insulating the available fuel sources from the material source with a fire-resisting “char” layer.
- Dilute the flammable gases and oxygen concentrations in the flame formation zone by emitting water, nitrogen or other inert gases.
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Q: What types of products use flame retardants?
A: While an ever-evolving list of new products—from hair dryers and small appliances to laptops and flat-screen televisions—is incorporated into our homes, offices and commercial environments, we seldom think about how the products are made. Flame retardants provide consumers with a critical layer of fire protection and are vital to reducing the risks associated with fire.
Today, flame retardants are used predominantly in four major areas:
Electronics and Electrical Devices
- Television and other electronic device casings
- Computers and laptops, including monitors, keyboards and portable digital devices
- Telephones and cell phones
- Washers and dryers
- Vacuum cleaners
- Electronic circuit boards
- Electrical and optical wires and cables
- Small household appliances
- Battery chargers
Building and Construction Materials
- Electrical wires and cables, including those behind walls
- Insulation materials (e.g., polystyrene and polyurethane insulation foams)
- Paints and coatings which are applied to a variety of building materials, including steel structures, metal sheets, wood, plaster and concrete
- Structural and decorative wood products
- Roofing components
- Composite panels
- Decorative fixtures
- Natural and synthetic filling materials and textile fibers
- Foam upholstery
- Curtains and fabric blinds
Transportation (Airplanes, Trains, Automobiles)
- Overhead compartments
- Seat covers and fillings
- Seats, headrests and armrests
- Roof liners
- Textile carpets
- Sidewall and ceiling panels
- Internal structures, including dashboards and instrument panels
- Insulation panels
- Electrical and electronic cable coverings
- Electrical and electronic equipment
- Battery cases and trays
- Car bumpers
- Stereo components
- GPS and other computer systems
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Q: Why are flame retardants important to use?
A: Experts recognize the use of flame retardants is essential to stopping or slowing the spread of fire. Flame retardants are used to prevent ignition by increasing the threshold required to start a fire; reduce the spread of fire; and delay flashover, the “fireball” that can quickly occur when the combined heat and the release of flammable gases cause automatic combustion. Delaying flashover reduces the rate and intensity of burning and increases the amount of time people have to escape.
The use of flame retardants is especially important today because modern homes, with the increase in electronic products alone, present a greater risk of fire dangers. In addition, flame retardant use is a component in protecting the public, particularly more vulnerable populations, including the elderly, children in schools and those in hospitals. According to the National Fire Protection Association, in 2009, 1,348,500 fires were reported in the United States, causing 3,010 civilian deaths, 17,050 civilian injuries and $12.5 billion in property damage. Flame retardants are the hidden protection against the potentially devastating impact of fire in so many products that we take for granted. Their benefits are often noticed only when they are not present.
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Q: Are all flame retardants the same?
A: Flame retardants are not all the same, and they are not interchangeable when it comes to the fire safety of materials and products. A variety of flame retardants is necessary because the elements in flame retardants react differently with fire. In addition, materials that need to be made fire-resistant are very different in their physical nature and chemical composition, and they behave differently during combustion. As a result, chemical manufacturers have developed different flame-retardant chemistries to suit different products to render them fire-resistant and allow them to retain their intended functionality and performance standards. Further innovation by the chemical manufacturing industry will be required to keep pace with advancements in technology, and, with it, a steady increase in new products. Read more about the common classes of flame retardants.
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