Flame-resistant (FR) garments are an important safety item for workers in the power industry. However, protection varies based on the arc rating of the clothing. Wearers must understand how the FR clothing they select can and cannot protect them.
For many professionals, flame-resistant (FR) clothing is an essential tool of the job. High-quality, specially engineered FR garments protect the wearer from burns caused by flash fires, electric arcs, and combustible dust. This allows professionals in a number of industries to tackle potentially dangerous tasks. Over the years, FR clothing has saved countless people from serious injury and even saved lives.
Flame-resistant clothing refers to any garments that are specifically designed to protect the wearer from flames and thermal injury. FR clothing resists ignition and self-extinguishes once the source of the ignition is removed. This helps to prevent burns from both initial exposure to the flames and from residual heat transfer.
1. Workers in the power industry face many hazards while on the job. Among the most serious dangers is exposure to an arc-flash. Flame-resistant clothing is vitally important to a worker’s protection during such an event. Courtesy: All Seasons Uniforms
Flame-resistant clothing is used in a large number of professions including the fire service, research labs, electrical utilities (Figure 1), and oil and gas. Workers in all of these areas often face the potential for explosions, open fires, and other thermal incidents, so it’s essential they’re properly protected when they’re on the job.
What Is Flame-Resistant Clothing?
When exposed to fire or an explosion, a lot of fabrics will ignite and continue to burn. Some will also melt onto the wearer’s body. This can cause significant injuries as textile fires often burn longer and result in more damage than the initial incident.
Flame-resistant clothing is specially designed so that it’s less likely to catch fire when exposed to combustion and high temperatures. In cases where the fabric does ignite, it won’t continue to burn once the heat source is removed. This gives the wearer valuable escape time and helps to minimize injuries. However, it’s important to remember that flame resistant doesn’t mean fireproof, and all flame-resistant clothing will burn if it’s heated for a long enough period of time.
Clothing that is flame resistant is generally also designed so that it doesn’t break open when heated. Open areas in the fabric would expose the skin to further hazard and potentially increase the severity of injuries.
How Does Flame-Resistant Clothing Work?
Most FR clothing is made from material that is designed to be resilient to heat. Materials like Nomex, Kevlar, and Modacrylic have excellent flame-resistant qualities and are commonly used to make elements of FR garments. Other fabrics, such as cotton, are naturally resistant to flames and can be treated with specialist chemicals to boost their heat resistance and their protective qualities.
Materials that are naturally flame resistant, and those that are treated with specialist chemicals, will behave in broadly the same way. These materials won’t keep burning when the source of combustion is removed, won’t ignite easily, and won’t melt. This last point is very important, as burning, melted fabric can do a lot of damage and cause serious, lasting injuries.
Different flame-resistant materials offer different benefits. What protects a person in one setting might not be suitable for another, so it’s essential professionals and employers always check which products are best for their workplace.
How Flame-Resistant Clothing Is Rated?
When buying flame-resistant clothing, it’s important to know exactly how much protection each garment offers. FR clothing is categorized using an arc rating, or an Arc Thermal Protective Value (ATPV). This rating indicates how much heat will be transferred through the fabric in the event of an arc flash, and therefore, how much protection the clothing will offer the wearer.
Preventing heat transfer can significantly reduce the impact of a fire or arc flash and help to protect the wearer from the worst effects of the incident. The values used to determine arc ratings are expressed as calories per square centimeter. The higher the arc rating, the more protection the piece of clothing will provide. An arc rating of 4 is suitable for a task assessed as a Hazard/Risk Category 1 (HRC1), the lowest risk, while an arc rating of 40 or more will protect the wearer when carrying out tasks assessed as Hazard/Risk Category 4 (HRC4), the most severe risk.
Manufacturers are required to indicate the arc rating of their garments and most will list this crucial number on their labels. Wearing multiple layers of arc-rated clothing will increase protection against heat and flames. Three or more layers are often required to tackle the most hazardous tasks.
While all arc/APTV-rated clothing is flame resistant, it’s important to remember that not all flame-resistant clothing is arc rated. Some FR clothing is simply made with flame-resistant fibers and hasn’t been lab tested to ensure it meets set standards. Investing in products that have been thoroughly tested is the best way to ensure adequate protection against potential hazards.
Types of Flame-Resistant Clothing
This type of personal protective equipment (PPE) is used by people in a wide variety of professions. As a result, there is an excellent choice of flame-resistant garments on the market.
2. Just as hard hats, gloves, impact-resistant glasses, and ear protection are common safety gear for power plant operators, flame-resistant clothing is also important. Wearing multiple layers of arc-rated clothing can offer the greatest protection. Courtesy: All Seasons Uniforms
A lot of professionals choose to wear flame-resistant outerwear over their normal clothes (Figure 2). Garments like overalls, high-visibility jackets, bomber jackets, and coveralls provide the wearer with extensive protection from potential hazards. Specialist items, such as balaclavas, face mufflers, and lab coats, are also available for professionals working in niche areas.
While some FR clothing is designed for settings where the wearer is constantly exposed to high levels of heat, other garments are meant for more intermittent danger. These are known as primary and secondary protection, and it’s important to know which you need before you invest in your FR outfit.
Style and Substance
For a long time, flame resistant meant bulky and ugly. Luckily, over the past few years, FR clothing has become a lot more stylish. You can now find FR jeans, shirts, polo tops, T-shirts, and hoodies that are designed to look good and be protective at the same time.
Most of these lighter garments offer lower levels of protection. However, layering them underneath a jacket or coverall with a high arc rating is a great way of adding crucial fire resistance to an outfit. This type of layering can help protect the wearer if the outer garments are burned or damaged, preventing burns and reducing the severity of injuries.
Flame-resistant clothing should always have a slightly baggy fit. Skin-tight clothes can transfer heat more easily to the skin, and this can result in more severe burns and injuries. Loose-fitting clothes create a layer of air between the garment and the skin, something that can help to insulate the wearer from heat and increase the outfit’s protective qualities.
The Limitations of Flame-Resistant Clothing
Flame-resistant clothes, while incredibly important pieces of PPE, are not fireproof. In extreme settings, the clothing will catch fire, and although it won’t melt onto the wearer’s body and will burn for a minimal amount of time, it can still cause serious injuries.
The best way to ensure that FR clothing is as safe as possible is to select garments rated to the correct standard. The minimum arc rating for HRC1 is 4, HRC2 is 8, HRC3 is 25, and HRC4 is 40. Layering FR clothing is an effective way of protecting the wearer from potential hazards. If the top layer is burned or damaged, the subsequent layers will help to stop the heat and flames from burning the skin and causing serious injuries.
As flame-resistant clothes are not fireproof, it is essential for professionals to avoid wearing synthetic garments under their FR clothing. Underwear, T-shirts, and other items made from flammable synthetic materials can cause a real hazard and can melt onto the skin, causing serious injury. Melting is possible even if the outer layer of clothing doesn’t catch fire. This is why it’s so important for professionals to wear appropriate clothing from head to toe.
Flame-resistant clothing also won’t protect against explosive forces, projectiles, and other hazards professionals may encounter while at work. If entering a situation where other hazards are expected, professionals need to ensure they’re wearing the correct PPE for the situation. Some of this PPE may also be flame resistant, increasing the protective qualities of the outfit.
Quality Flame-Resistant Clothing
PPE should always be sourced from trusted, experienced suppliers. Professionals need to know that the overalls, balaclavas, jackets, and mufflers they’re wearing will protect them in case of a thermal incident. The best way to ensure PPE is up to standard is to invest in quality clothes from recognized manufacturers.
Trusted manufacturers will list the arc rating of each garment clearly on the label and provide important information on the materials used to make each item of clothing. Understanding the protective properties of each piece will help professionals properly protect themselves while they’re on the job.
Flame-resistant clothing can dramatically reduce and even prevent injuries in case of a flash fire, electrical arc, or explosion. This makes FR clothing an essential piece of PPE for people working in a variety of industries. Investing in good-quality FR clothing, and carefully checking ratings and requirements, can help to keep professionals safe while they’re tackling even the most dangerous of tasks.
—Nick Warrick is the sales manager at All Seasons Uniforms, a professional workwear company based outside of Chicago that has been in business since 1991.