Arc flashes, also known as electric arcs, are a common hazard that can have severe consequences for workers. Providing them with adequate personal protective equipment (PPE) is essential. Here are five key steps to follow when selecting clothing for arc flash protection.
1. Understand arc flash risk
Essentially, an arc flash is a plasma fireball resulting from a short circuit between two conductors such as busbars or cables. It can reach temperatures of up to 20,000°C, which is enough to ignite a worker’s clothes, even at a distance. It can lead to severe external and internal burns and even fatal injuries.
In May 2021, Network Rail was fined nearly £700,000 after a worker suffered third-degree and mixed depth burns due to an electrical arc. This is just one example of the far-reaching consequences that electric arcs can have for both workers and employers.
The latest Eurostat figures show that over 76,000 workers in Europe suffered injuries due to “contact with electrical voltage” in 2018. And with the renewable energy sector continuing to grow, arc flash may become even more widespread in years to come. Renewable energy generators such as solar panels and wind turbines as well as battery energy storage systems all present arc flash hazards.
2. Assess the risk
The best way of addressing arc flash risk in the workplace is the so-called 4P Methodology, which includes four key steps:
- Predict the severity of the arc flash
- Prevent damage through hazard mitigation
- Protect workers from any residual hazard
- Publish the results.
PPE such as protective clothing is a key component of the third step and must be compliant with the latest standards.
3. Keep on top of compliance
Arc flash-protective clothing is certified by different standards that often vary from region to region. What these standards have in common is that they determine whether a fabric can protect a worker against electric arcs by preventing ignition.
The main European standards are IEC 61482-1-1:2019, IEC 61482-2:2018, and EN ISO 11612. Some protective clothing undergoes additional testing that determines the amount of transferred energy using an instrumented manikin (as specified by ISO 13506-1:2017). This way, the protective clothing’s resistance to short-duration flame engulfment can be assessed more accurately.
4. Select the right clothing
Can it prevent ignition when exposed to intense heat? This is the single most important question to ask when looking for arc flash-protective garments. Look for fabrics that are designed to carbonise and thicken when exposed to heat. This means they can protect a worker against burns by forming a protective barrier between the heat source and the skin.
Another important feature to consider is durability. Choose fabrics that preserve their heat resistance even after having been washed repeatedly.
Multi-hazard protection is another important consideration. Some applications may require clothing that integrates multiple layers of protection, including resistance to heat, flame, and molten metal splashes.
Comfort is also paramount. Uncomfortable garments can lead to fatigue, so always opt for lightweight and highly breathable fabrics.
5. Keep up to date with materials science
Heat and flame-resistant fabrics are constantly evolving so keeping up to date with the latest developments is a must. For example, double-faced fabrics, also known as “bubble-effect” technology, represent a recent innovation in arc flash protection.
These new materials are designed to form air bubbles inside the internal layer when they are exposed to heat. This design provides greater electric arc flash protection than a conventional fabric with the same material composition and weight. The ATPV (Arc Thermal Performance Value) of a double-faced fabric is between 16 and 19 cal/cm2, which is more than double the ATPV of an equivalent conventional fabric (7.2 cal/cm2).
Protective clothing is critical to keeping workers safe from arc flashes. Double-faced fabrics are proving the optimal choice in this area, delivering enhanced heat and flame resistance without compromising on comfort.
Pauline Weisser is an application development specialist at DuPont Personal Protection