Many workers are presented with thermal hazards such as molten metals, arc flash, hot liquids, and flame. In environments where these hazards are present, flame-resistant (FR) personal protective equipment (PPE) is of paramount importance. When selecting such gear there are many important terms that one may be confronted with. The most common distinction is inherent fabric vs. treated fabrics.
Want more information on fr fabrics? Feel free to contact us.
A piece of protective equipment can be classified as an inherent fabric if it is woven using some percentage of a fiber that is itself chemically flame-resistant. These are generally oxidized fibers or fibers synthetically derived from petrochemicals that have been chemically altered. In such garments, the flame-resistant properties are inherently present in the fiber’s polymer structure and can never be lost due to washing the garment.
Protective equipment may be labeled as a treated fabric if fibers have been chemically treated to achieve FR properties, either before weaving or as a chemical finish on the garment. Some treated fabrics can lose their FR capabilities over time or with frequent or improper washing, although advances in the FR field have produced treated fabrics that retain their protective qualities for the entire lifetime of the product. The first such treated fabric was introduced in 1987, and the difference in efficacy between treated and inherent FR fabrics has been shrinking ever since. Even so, many purchasers of FR equipment turn instead to inherent fabrics or inherently flame retardant fabric due to the ongoing misconception that all treated FR garments will lose their protective properties over time.
Inherent vs. Heat Treated Fabrics
Heat-treated fabrics are materials made from the addition of flame-retardant chemicals to provide some level of flame resistance. The additive forms a strong bond with the polymer of the fiber, which is often itself not flame-resistant. This bond is difficult or impossible to remove when proper laundering and care is applied. One potential pitfall of such gear is that there is no way to visually inspect that the FR quality of the equipment is intact. If outside the useful lifetime of the equipment, or if improperly laundered, the FR qualities may be reduced or removed with almost no way to determine that this has happened.
This problem is not present with inherent FR fabrics, as the chemical properties of the fibers themselves cannot be washed out. This may cause inherent fabrics to sell at higher costs since they typically offer longer useful lifetimes. Since there is no regulatory body governing the use of this term, however, it has often been applied loosely—often to garments containing no more than 15% FR fibers blended with naturally flammable fibers. Some garments that are woven of natural fibers treated before the weaving process have even been marketed as inherent, so to some extent, the term has lost meaning.
Inherent FR Fabrics: Pros and Cons
The primary advantages of inherent FR fabrics include:
- High level of protection from thermal hazards
- Often present higher thermal protective performance (TPP) scores than treated fabrics
- Long service life
- FR properties will never wash out
- Garments will not ignite in normal O2 concentrations
- May char or expand (typically garments created with oxidized fibers) to provide increased thermal resistance under continuous exposure to a thermal hazard
- Lightweight
The most notable disadvantages of inherent FR fabrics include:
- Higher upfront cost (albeit offset by longer useful lifetime)
- Purportedly less comfortable than some treated fabrics of cotton or other cellulosic origins
- Inconsistency in application of the term ‘inherent fabric’ or ‘inherently flame retardant fabric’ that is often driven by marketing motives, rather than science and metrics relating to performance
Treated FR Fabrics: Pros and Cons
Here are some of the primary advantages of treated FR fabrics:
- Cheaper than most inherent garments
- Many available treated fabrics now provide life-of-garment FR protection
- Generally considered more comfortable
- Many available treated fabrics now only char similar to inherent fabrics, rather than combusting when exposed to a heat source
- Most treated fabrics will spontaneously extinguish a flame when the source of heat is removed
The largest disadvantages of treated fabrics include:
- Some treated fabrics will lose their protective qualities over time
- Some treated fabrics off-gas as a method of flame retardancy, producing harmful gases that in some cases include gaseous cyanide
- Many treated fabrics use increased mass as a means of increasing FR metrics such as TPP, which can increase heat strain and decrease comfort when wearing a heavier garment for extended periods
- Some 88% cotton, 12% nylon (88/12 FR) and 100% cotton blends, in particular, lose their protective qualities over time with even proper laundering
- If the flame-resistant capabilities have diminished, there is no way to tell upon visual inspection
Tex Tech: The Industry Leaders in FR Fabric Technology
Even with an understanding of the differences and usages of terms such as treated and inherent, the key factor is ultimately the safety and protective value offered to the wearer. In this regard, a more important distinction is proven vs. unproven. Tex Tech and our CarbonX brand have repeatedly proven effective in laboratory testing, as well as in the field—all with the added benefits of comfort and affordability. We work primarily with inherent fabrics.
- CarbonX’s range hoods, gloves, undergarments, and other protective garments for industrial, motor-racing, and firefighting are superior in comfort and durability and made with inherent FR fibers.
- Tex Tech provides aircraft seat fire blocking with only inherent fibers—and nothing else blended in—that lasts for many years on an airplane
- Tex Tech offers high-tech Thermal Protection System (TPS) fabrics and materials for space launch vehicles to withstand rocket burn and the thermal stresses of re-entry
Tex Tech Industries has been a leader in the advanced textile industry for over a century. Throughout this time, we have devoted enormous resources to research and development in the areas of textile and fiber solutions. We have pioneered more than 7,000 of the best performing products in the marketplace and a wide range of high-performance materials.
We provide innovative solutions for all individual fabric requirements, backed with best-in-class customer service. We invite you to contact our experienced material scientists to discuss how to discuss how Tex Tech can provide the material solutions you need.
Contact Us
If you’re familiar with flame resistant clothing (FR), you’ve probably heard of terms such as treated fabrics and fibers or inherent fabrics and fibers. However, there are some key differences when talking about flame resistant fibers and fabrics. Failure to understand those differences could result in lapses in safety. It’s important to know how these fit in particular environments.
In this post, we’ll touch on the history of flame resistant fibers and fabrics. We'll define the terms mentioned above. We'll talk about some of the applications that they’re found in, and address how to clean and care for each type.
Some of this article might get a little technical...even a bit boring. But we want to break down some of the basics, no matter how dull they may seem. It's important to understand the various parts that make up flame resistant clothing.
It's also important to remember that garment care is critical with FR garments. Proper care guarantees that FR properties aren’t compromised. The goal will be to give you more information on the above so you can be safer in the workplace.
The history of flame resistant fibers and fabrics
It's widely agreed upon that flame resistant textiles were discovered in 1821. French chemist Joseph Louis Gay-Lussac first discovered that ammonium phosphates and borax were responsible for making textiles resistant to open flames. This discovery launched the flame resistant clothing industry we appreciate today.
Even as early as the mid 1600s, people in Paris were considering ways to reduce fire in theaters. At the time, they developed fireproof plaster and clay for buildings. This work encouraged others in the scientific community to work toward applying the same technology to clothing.
People viewed the development of flame resistant materials like we do today. They're used to prevent potential harm.
Fast forward to the 20th century, when scientists discovered that incorporating stannic oxide into fabrics made them resistant to flames. Stannic oxide is a powdery, off-white, product that's produced from high-grade tin metal. In time, these techniques added flame resistance to natural fibers.
Contact us to discuss your requirements of heat resistant cotton fabric. Our experienced sales team can help you identify the options that best suit your needs.
This is just a brief overview of the origins of flame resistant fibers and fabrics. For more in-depth coverage, check out this article. The author does a great job walking through the history of flame resistant clothing.
Flame Resistant Fabric: What is Treated Fabric?
Fabric is a combination of fibers that, when put with other pieces of fabric, make a garment. We think of fabric as the manufacturing stage between fiber and garment. Treated fabrics are those that have a flame retardant chemical applied to make them flame resistant. The fibers used in these fabrics aren’t usually thought of as protective. They become flame resistant because of the chemical treatment.
The fibers used in these fabrics are usually 100% cotton fibers or are some combination of cotton and nylon. Regarding durability, the fabric made up of cotton fibers provides little resistance to abrasion. The fabrics with the nylon fiber added to them perform much better with resistance to abrasion. Treated fabrics work well in utility, oil and gas, chemical, and petrochemical applications.
Care for treated fabrics should take place in water with a hardness of 1.5 grains (25ppm) or less. Less hardness is ideal as hard water contains mineral salts that can leave deposits on the fabric. These deposits could negate the flame resistant properties of the garment. Deposits could even serve as fuel if the garment comes in contact with an ignition source.
Flame Resistant Fibers: What are Treated Fibers?
Treated fibers are those that have a flame retardant chemical that’s applied during the fiber forming process. As a result, it makes the fibers, flame resistant fibers. Fabrics made from treated fibers are flame resistant for the life of the garment. The flame retardant chemical can’t be removed by normal wear or laundering. The garment would no longer be flame resistant only if it becomes torn or soiled to the degree that the soil won’t wash out.
One fiber type is a treated 100% rayon. Lenzing FR® is a synthetic cellulosic fiber made by Lenzing AG. These fibers get treated in the fiber forming process and are flame resistant forever.
Another fiber type would be a blend of cotton and Modacrylic fibers. Fabrics made of these fiber blends are characterized to have a soft and comfortable cotton-like hand. The Modacrylic fiber that gets added has soft and strong components. It’s also resistant to chemicals and solvents. This resistance makes these fiber types ideal in flame resistant environments.
Applications for these fiber types are a bit more general. Industrial protective clothing, utilities and fire fighter work uniforms are good matches. Like treated fabrics, it’s recommended that treated fibers get washed the same way. Water that is too hard could leave deposits that could ignite if exposed to an ignition source.
The only significant difference between caring for the two types is that the Modacrylic /cotton blends should be treated in soft water. Use a non-chlorine bleach as well so you don't weaken the fabric.
What are Inherent Fabrics and Fibers?
You don't need to treat inherent fabrics and fibers with chemicals. The FR properties are an essential characteristic of the fiber chemistry. Once again these fibers are FR fibers, but from the point of manufacturing of the fibers. Both inherent fabrics and fibers cannot lose their flame resistant properties from normal wear or laundering. The garment will keep its flame resistant characteristics throughout its life.
Modacrylic fibers are the most popular inherent fibers. They are most often found in blends with other inherent flame resistant fibers. The modacrylic fibers are often combined with various percentages of lyocell, para-aramid or polyamide imide fibers. These combinations make a durable fabric that meets NFPA 70E CAT2 and NFPA 2112 standards. Another popular inherent fiber is NOMEX. In clothing applications, NOMEX comes as a stand alone fiber or often in a blend with KEVLAR.
Inherent fabrics and fibers are found in petrochemical, electrical and utility industries. Another popular application is firefighter station wear and turn out gear. Most inherent fabrics and fibers are not recommended for use in welding operations or around molten substances. Caring for inherent fabrics and fibers is the same as the treated types. Soft water is recommended as hard water contains mineral salts that can leave insoluble deposits on the fabric. These deposits could negate the flame resistant properties of the garment. Chlorine bleach is also not recommended as it will weaken the fabric.
Bulwark provides much of this information as a leader in the flame resistant garment industry. This is also not necessarily an endorsement of Bulwark. There are other brands that manufacture high-quality flame resistant garments as well. The most important thing to understand is what fabrics and fibers build the garments that keep you safe while on the job. If you would like to schedule a demo of our private uniform store software, click the link below. We can make it easier for you to put your team in the proper safety apparel.
The company is the world’s best heat resistant fabrics supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.