An arc flash is an electrical explosion that is caused when high voltage electricity jumps from one electrical component to another across an air gap. Arc flashes produce blinding light, intense heat, deafening sound, molten metal shrapnel and/or a strong pressure wave that can cause serious injuries. Luckily, arc flash explosions are incredibly rare events, with 90 per cent of eletrical injuries coming in the form of electrical shock. It is important to wear all the proper arc flash PPE for your working conditions to help prevent injuries from both arc flashes and shock.
What Arc Flash PPE Do I Need?
Arc flash PPE is determined by either a category rating or by calculating the amount of energy that would be released in the arc flash, which is measured in calories per centimeter squared (cal/cm2). A calorie is the amount of energy required to raise the temperature of one gram of water by one degree Celsius at standard pressure. It is important to match up the risk to the proper level of protection to avoid serious injuries.
Most people think of an arc flash suit or ‘bomb suit’ when they hear the term “arc flash PPE”, but basic FR coveralls tend to have around 6-8 calories of protection and are suitable for protecting against lower energy arc flash risks. There are also arc flash suits that offer up to 140 calories of protection, which is well beyond the often used category 4 level of protection at 40 calories.
When selecting the right arc flash PPE, there are some important factors to consider:
Face Shield Colour
Arc flash face shields are a critical piece that not only protect you from the impact of flying debris, but also contain an infrared dye that absorbs the heat from the explosion to protect you from a severe burn. Historically this dye has created a greenish yellow tint to them which causes issues with the perception of colours, particularly when identifying greens from blues as well as yellows from whites.
The best arc flash shields on the market are now available in grey which offers no colour distortion which allows users to see different colours clearly and accurately as pictured here. This limits the issues of a user having to expose their bare face to a hazard when lifting their visor to see clearly.
Arc Flash Clothing Material
When selecting clothing to protect against an arc flash, it is important to pay attention to the materials itself. Workers are spending more and more time in their workwear these days and it is important that they are comfortable. This will reduce the stress on the worker and thereby reduce the chance they are distracted by their clothing which leads to accidents.
Arc flash suits can be purchased in ultra-light weight materials which mean they are lighter, have more breathability and are much cooler to wear.
Lighting on your face shield or hood is a critical part for electrical workers as they tend to be working in electrical boxes or areas with limited space. Using floor lamps creates the problem of your body casting shadows onto your work area because the lighting typically needs to be located behind the worker.
Task lighting should play a role when deciding which face shield or arc flash suit is best for you and your workers. Your lighting options should be located on the forehead and have vertical adjustability so it is above your eyes and you don’t have to tilt or move your head to focus the light on the work area. The lighting option should also be bright enough for the task and have a long enough run time to complete the job.
Ventilation is not as critical when it comes to face shields as they are open on the sides, but when it comes to your arc flash hood, getting fresh air delivered into the hood can play an important role in worker comfort and performance. Fresh air pumps can deliver a gentle flow of air into the hood to help prevent fogging of the face shield as well as keep the air from becoming stale and saturated with CO2.
Levitt-Safety works with the leading manufacturers of arc flash PPE – including Oberon, PMMI, and many others.