Fire Data at Industrial Facilities

The National Fire Protection Association (NFPA) notes that an average of 36,800 fires occur yearly at industrial and trade properties. Of these, 8000 fires were structural ones. Structure fires transpired in “manufacturing or processing properties including utility, industrial, defense, agriculture, and mining properties.” Structural fires reported had by far the most civilian injuries and the related losses from these fires include about $1.5 billion in direct property damage. This does not consider lost time and effort that needed to be refocused towards the destructive events.

The use of flame retardant ductwork in facilities that are considered at risk is a smart and inexpensive way of mitigating what could otherwise be very damaging and costly.

Facilities that deal with “combustible dust” and other materials that can easily catch on fire should take precautions to reduce the possibility of fires. A combustible dust is any solid that has the ability to catch fire and explode when exposed to a detonation source. Combustible dusts include powders, flakes, fines, fibers (i.e., cotton), most solid organic materials (such as sugar, flour, grain, wood, etc.). These may not always be considered combustible, but they can burn or explode if the particles are the right concentrate and the environment is ripe for it.

The National Fire Protection Agency (NFPA) defines combustible dust as “a finely divided combustible particulate solid that presents a flash-fire hazard or explosion hazard when suspended in air or the process-specific oxidizing medium over a range of concentrations” in Standard 652-2019, The Fundamentals of Combustible Dust.

Material Handling Flame Retardant Ducts

When dry materials like grains and wood dust are processed and moved, they pose serious concerns to the facilities that house them. Dry ingredients are far more prone to combustion because of the lack of moisture in the product. Woodworking dust alone has a plethora of wood varieties and sizes that behave differently when moved or processed. Having flame-retardant parts within processing plants is helpful in mitigating the risk of growth in fires. A fire may happen, but having the resources to quelch it or to keep it to a limited space will reduce the possibility of injury, damage and costs.

We offer fire-rated ductwork that is designed to move dry bulk materials. Our fire retardant hoses range from neoprene dipped polyester ducts that offer greater flexibility and are often demanded by tight spaces. These are very durable canvas-like flexible ducting that have excellent flex-fatigue properties.
Neoprene Flex – 1 Ply Flexible Ducting
Neoprene Flex – 2 Ply Flex Hose
Neoprene Flex – 2 Ply WS Material Transfer Duct

These flame retardant hoses are recommended for light duty, low pressure applications and can be used to move bulk materials and/or light dust. As a class they are extremely flexible, with the thinner walled 1-ply version being more flexible, yet less durable. As the thickness of the duct’s wall increases, so does its durability, which makes for a less compressible and flexible hose.

The Neoprene coating offers excellent abrasion and chemical resistance and these flex ducts are available in sizes from 1.5-inch to 24-iunch in diameter. The Neoprene Flex series have a maximum temperature of 250°F.

Poly Fabric Flex – Series of Fire Rated Ducting

This series of fire rated ducts are made from PVC vinyl coated polyester fabric hose reinforced with a spring steel wire helix & external PVC wearstrip. The ductwork’s wearstrip gives additional external abrasion & drag resistance, which is useful if the hose is being moved around in rough environments. Since it is made with PVC, these fire-retardant hoses offer great chemical & moisture resistance
Poly Fabric Flex – 1 Ply Industrial Ducting
Poly Fabric Flex – 2 Ply Industrial Hose
Poly Fabric Flex (Bridge)

We also offer material handling hoses made with neoprene and polyurethane that are flame retardant materials. Neoprene and polyurethane are chemically resistant materials and offer excellent durability when faced with abrasion. These flexible ducts have excellent resistance to harsh chemicals, which makes a fire resistant hose a great choice for tasks requiring the movement of dry bulk and other abrasive materials. Both duct materials are known for their excellent resistance to weathering as well as their flexibility, providing you with the added benefit of extra protection without sacrificing the flexibility of your fire resistant hose. Wear strips and other reinforced hose safeguards are important because protecting the exterior of your flame retardant duct hose is virtually just as crucial as safeguarding the interior. Even the slightest tears or breaks in the material can lead to drastic losses of performance.

What Facilities are at Risk for Dust Fires?

When fine particulates that are flammable are moved through industrial machinery, they can be exposed to static buildup. Static buildup is when electric charges are exchanged between the surfaces of two objects that come into contact with each other. One entity takes on a positive charge and the other material will take the negative charge. It is due to this that static electricity builds up on the surface of substances. Materials like fertilizer, compost, grain, sugar, plastics, pharmaceuticals and woodworking chips/dust are some examples of at-risk products.

These types of materials are sometimes processed in small pieces like fertilizers and sometimes dust is a byproduct when materials are handled and processed. Dust is also created by abrasive blasting, cutting, crushing, mixing, sifting or screening dry materials. For example, fertilizers are generally sized between 1 and 5 mm. A uniform particle size allows for an even coverage on the field, which is why fertilizer is processed and handled to route the proper sizing. All of this movement of materials could be a source of static buildup or the fertilizer dust suspension in the air.

What Does a UL Certification Mean?

UL is an acronym for Underwriters Laboratories, a private testing and certification enterprise that was founded in 1894 in Chicago. Underwriters Laboratories certify products that consumers and companies alike can count on in order to promote and certify safer products for both workers and consumers. Naturally UL approved components should be used where there is a danger or event of a fire. A flexible duct that is part of machinery or installed as an aftermarket hose onto or becomes a part in an apparatus needs to ultimately meet the UL standard for flammability. Using UL approved parts in OEM equipment or in the aftermarket, is good practice maintaining safety standards through the use of tested and certified products.

What is UL 94?
UL 94 is a flammability standard for plastics by Underwriters Laboratories. The standard classifies plastics in various groups according to how they burn. There are six UL 94 classifications. These classifications relate to materials commonly used in manufacturing enclosures, structural parts and insulators found in consumer electronic products (UL 94 5VA, 5VB, V-0, V-1, V-2, HB). The requirement for a UL 94 V-O is that the samples may not burn with flaming combustion for more than 10 seconds after either application of the test flame.

Meaning that the materials that the samples are made of do not act as fuel for the fire. Once the source of the fuel is gone, the fire should die off. Also, it is expected that the samples do not drip flaming bits that can ignite neighboring materials. Flame retardant ducts and their material makeup must follow these guidelines in order to get the UL 94 V-O approval.

How Fires Burn and How We Can Help!

To burn, a fire needs three ingredients: Fuel, oxygen, and ignition. Fuels can comprise anything that is combustible, like wood, paper, and grains. A fire must be in an ecosystem where there is oxygen. Lastly a fire needs a “source of ignition.” Since the source of ignition is more often than not unknown, and since oxygen is a component of all ecosystems, we cannot proactively limit their presence. However, limiting the amount of fuel that the fire will feed on is the goal of UL. 94 V-O through the use of flame retardant materials in industrial and electrical apparatus. At Ducting.com, we offer a wide range of products that are made with materials that are officially classified as fire retardant. Our inventory of ducting products includes hoses intended for light-duty air applications to heavy-duty chemical and abrasive material transfer work. Take a look at our extensive catalog of flame retardant duct hose today to find the right tool for your job. If you have any questions about the classification of fire retardant materials or which ducting product is best for your needs, give one of our ducting experts a call today!