Our Dangers of Improper Wear series examines many of the common mistakes people make when wearing arc-rated and flame resistant (AR / FR) clothing, with real-world arc flash video footage that shows just how substantial each mistake can be. In each episode, you’ll find powerful examples of why wearing the right PPE, and wearing it properly, makes all the difference – with expert commentary from Scott Margolin, Vice President of Technical.
In today’s episode, we’re looking at the consequences of wearing flammable outerwear over AR garments. In this case, a flammable high-visibility vest and jacket over CAT 2 arc-rated (AR) dailywear. The video below graphically shows the consequences of wearing flammable clothing over quality AR clothing. So, be sure to watch with a mindset of what not to do when layering for protection against arc flash hazards.
As shown in the video, the arc immediately ignites the flammable hi-vis vest and jacket. The more flammable outer layers you wear, the more fuel there is to burn, which means your clothing is on fire for a longer period of time, resulting in more severe injury.
This particular manikin was also wearing a face shield and chin cup. The fire fueled by the flammable vest and outerwear was so aggressive and long-lasting that it actually melted the face shield and chin cup. Arc rated face shields and chin cups are designed to withstand an arc flash, however, they are not designed to withstand a fire of that duration. Additionally, in a catastrophic fire – like the one shown in the video – there is no way to avoid breathing in fire, which is as dangerous to your health as it sounds
After we put the fire out we were able to examine the AR layer underneath the flammable vest and jacket. The AR layer was remarkably intact considering the severity of the fire. However, a wearer exposed to an arc flash while wearing flammable outer layers would still be burned through the AR layer for two reasons:
- Molten polymer was the outer layer, and is now all over the AR garment, and molten polymer is much more efficient at transferring heat than air.
- AR garments are not designed to protect you from a sustained fire lasting more than a few seconds.
When getting dressed in your AR garments for a day on the job, you must make sure your garments, especially, your outer layer is rated for the hazards you could face in the field.