The Evolution of FR Denim
Today's workers are looking for the fits, features, and finishes of retail-ready denim but with proven flame-resistant protection.
Back in the mid-1800s, the news of gold being found brought more than 300,000 gold-seekers to California, and the gold rush boom in the United States served as the catalyst that propelled denim into the mainstream. Today, gold is doing it again, but this time it's black gold. The increase in U.S. oil and gas production in during the past decade is proving to be another catalyst for denim, and this time it includes flame-resistant denim.
Researchers at FracTracker.org estimate that there were more than 1.1 million active oil and gas wells operating in the Unites States in 2014, which is a significant increase over the approximately 774,000 oil and gas wells reported by the U.S. Energy Information Administration in 2004. This rise in the number of wells has resulted in a more than 50 percent increase in non-supervisory employment in the mining, quarrying, and oil and gas extraction sectors. Although the recent trend in the price of crude oil has led to some contraction in the industry, the number of workers who need protection from the hazards of flash fire and electric arc flash remains at near-record levels.
Jeans have become a staple in every wardrobe, and the popularity and acceptance of jeans from the workroom to the boardroom have led to the rise in the number of fits and finishes available. According to several surveys, the average American owns seven pairs of jeans, which means that variety is a very important factor when it comes to jeans--including those worn for protection from flash fire and electric arc flash. But just because someone is wearing FR denim doesn't mean that he has to look as if he's just stepped out of a 1970s catalog. Today's workers are looking for the fits, features, and finishes of retail-ready denim but with proven flame-resistant protection.
NFPA 2112 is the Standard on Flame-Resistant Garments for Protection of Industrial Personnel against Flash Fire. It requires testing of a standard garment by ASTM F1930, a test method used to provide human skin burn injury prediction. NFPA 2112 dictates that FR fabrics must record no more than 50 percent predicted body burn after a 3-second exposure at 2 calories/cm2 or a total thermal energy exposure of 6 calories/cm2. Three garments are tested, and the average predicted percent body burn is reported for the FR fabric. While the data from this test should not be considered a prediction of performance in an actual flash fire incident, it may be used to compare different protective fabrics under a standard set of laboratory test conditions.
Properly constructed and treated denim fabrics used for flame-resistant jeans will typically range from 11.5 to 14.75 ounces per square yard and have a predicted percent body burn rating of less than 10 percent as determined by ASTM F1930, positioning denim among the most protective and durable of FR fabrics--and therefore making it worthy of consideration in your company's PPE strategy. In addition to the protection offered, the case for selecting jeans to meet your FR clothing needs is also about satisfying the desire for denim and meeting the lifestyle needs of your workforce.
Considering all of this, what are some of the things that you can look for to help you select an FR denim program for your workforce that looks, fits, and feels like retail-ready jeans?
Many producers of FR denim can incorporate the fashion looks that are popular today into their flame resistant lineup, including fabrics that simulate the look of vintage denim fabrics through the use of yarn character created by introducing visible variations of yarn thickness. The spinning techniques used to create these effects should be tightly controlled to maintain the quality and integrity of the yarn, as you never want to sacrifice strength and durability for fashion. Premium denim shades, which add richness and fashion appeal to protective garments, are another way to provide even more choices to the selection of FR jeans available to your workers.
When it comes to comfort, soft-hand finishes help create a more comfortable, ready-to-wear FR denim jean that doesn’t sacrifice the durability and longevity of the FR protection. Consider flame-resistant denim that is mechanically softened with open width, continuous fabric processing using air under pressure because it results in FR denim that is softer on both sides of the fabric. An added benefit of denim that is mechanically softened is that the softness won't wash out, which can happen with topical softeners. This type of mechanical softening process will also avoid unsightly "rope marks" that can occur when denim is softened in rope form.
The addition of flex to FR denim not only adds to the comfort of the garment, but also helps create the more up-to-date fits that are popular today, particularly among women. Two numbers are important to look for when considering flex denim: the percent of "stretch," which should be in the low teens, and the percent of recovery, which should be as close to 100 percent as possible, enabling the garment to retain its shape after flexing. Some flex denim fabrics have a bilateral flex, which allows them to elongate sideways and diagonally. This eliminates any sagging or bagging in the garment and makes reaching and bending easier for workers.
Manufacturers of FR denim are also beginning to incorporate unique fiber blends into their fabrics to enhance the comfort and wear properties of denim. One recent example is the introduction of cotton blended with Tencel®, which is the strongest cellulosic fiber available. This particular blend enhances the softness and comfort of flame-resistant jeans without a tradeoff in durability. And despite the added strength of the fabric compared to 100 percent cotton, denim made with Tencel feels lighter than its true weight, which adds to the overall comfort of the garment.
Laundering FR Garments
Many producers of FR fabrics guarantee the flame resistance for the expected life of the garment, as long as the recommended laundering instructions are followed. If your workers are laundering their FR jeans at home, it is very important that they follow these instructions to ensure they do not compromise the level of protection that’s been built into the fabric:
- Garments made from FR and non-FR fabrics should be washed separately to prevent cross contamination, so workers should not throw their flame-resistant jeans into the same load as their favorite non-FR pairs. Turning FR denim jeans inside out before laundering will help to prevent streaking and reduce color loss.
- The objective in cleaning any FR fabric is to remove flammable soils and not to add anything that might reduce the FR properties of the garment. Therefore, flammable materials such as starch and fabric softener, which can accumulate on garments over repeated launderings, must not be used on FR jeans.
- Chlorine bleach and oxygen bleach (e.g., hydrogen peroxide), either alone or in combination, must not be used on FR treated fabrics. Repeated exposure to bleach will damage the flame retardant polymer, reducing the flame-resistant properties of the garment. However, powdered detergents containing "color safe" bleaches, such as sodium perborate, may be used, and laundry detergent can be poured directly onto heavy stains to pretreat them and aid in removal.
- Dryer sheets should not be used with any FR fabric because the softeners in them could build up on the fabric surface, reducing the flame-resistant properties of the garment.
If Made in America is important to you, be sure to understand where each component of the FR fabric was produced. Does the fabric manufacturer use cotton fiber that was grown in the United States, which is in high demand these days due to its reputation for quality? Is the yarn spun in the United States, and where is the fabric woven? Does all of the fabric dyeing and FR finishing take place in the United States? Answering no to any of these questions means that the FR fabric wasn't 100 percent produced here. In addition, if the fabric wasn’t made in the United States, can the manufacturer tell you where it was produced? When a manufacturer is unable to track the production of FR fabrics or even make it themselves, workers should consider that there may be a decreased level of quality control and reliability, which is of utmost importance when it comes to FR clothing.
Today's workforce can finally have the needed protection and the desired look in an FR jean they enjoy wearing, both on and off the job. The rising popularity of flame-resistant denim appears to indicate that FR jeans will be more of a long-term staple than a passing fad. With increased availability of styles, washes, and fits, denim will continue to grow in FR applications.
This article originally appeared in the March 2015 issue of Occupational Health & Safety.