Nomex FR Apparel Newsletter

The Advantages of Inherent Flame Resistance

Many different fibers can be used to make flame-resistant (FR) garments. All fibers are either inherent or non-inherent.

Inherent Fibers and Fabrics

Inherent fibers are made of substances or materials that are not flammable; do not support combustion; and do not provide fuel for a fire. The thermal protection of inherent fibers is permanently part of the fiber chemistry and goes completely through each and every fiber—end to end, down to the core. The solid layer of FR protection of inherent materials cannot be stripped off, washed out or worn away, no matter how the garment is used or laundered.

Inherent Fabrics

DuPont™ Nomex® and DuPont™ Kevlar® are both inherent FR fibers made by DuPont for high-temperature applications.


Non-inherent Fibers and FRT Fabrics

Non-inherent fibers, such as cotton, nylon and polyester, are flammable in their natural state. When exposed to heat or flame, they become fuel for the fire. To make a non-inherent material flame-retardant, a chemical must be applied to the outer surface of a fabric.

Unlike fabrics made with inherently FR fibers, flame-retardant-treated (FRT) fabrics may have their FR properties diminished or removed depending on how they are laundered; how many times they are laundered; or if they are exposed to certain chemicals in the laundering process or work environment. Many garments made of non-inherent fabrics contain sewing thread and zipper tape made of Nomex® because of the permanent flame resistance of Nomex® fiber.

Inherent FR Technologies from DuPont

Inherent FR Technologies from DuPontUnderstanding the basic differences between inherent FR and non-inherent FRT technologies is very important to those responsible for evaluating, selecting and wearing FR garments. Nomex® IIIA, Nomex® Comfort, Nomex® MHP and DuPont™ Protera® fabrics are inherently flame resistant and provide excellent protection from fire and arc flash hazards.

Fabrics and garments made from Nomex® have been third-party certified to meet the requirements of National Fire Protection Association NFPA 2112 Standard on Flame-Resistant Clothing for Protection of Industrial Personnel Against Short-Duration Thermal Exposures from Fire. These materials deliver superior protection across a range of possible fire exposure conditions.

"Nomex® MHP and Protera® are specifically engineered by DuPont scientists to protect against dual threats of flame plus electric arc hazards"

Fabrics and garments made of Nomex® IIIA are lightweight and very durable, with a long wear life and long history of proven performance. Nomex® MHP and Protera® are specifically engineered by DuPont scientists to protect against dual threats of flame plus electric arc hazards, meeting or exceeding all NFPA 2112 fabric requirements with the added safety of Category 2 arc flash protection (NFPA 70E® Standard for Electrical Safety in the Workplace). Just like Nomex® IIIA, the FR properties of fabrics made of Nomex® MHP and Protera® come from inherently FR fibers and cannot be stripped off, washed out or worn away.

Learn More

To learn more about inherent vs. non-inherent FR, read the DuPont™ Nomex® Thermal Technical Bulletin, which includes answers to frequently asked questions.

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