31 July 2018
For the thousands of workers in electrical engineering, the risk of an arc flash incident is a daily reality. Until now, employers have had to balance protection against wearer comfort. Gordon Burns describes the latest developments in PPE.
EMPLOYEES OF electricity companies have long had particularly high demands made on their clothing. Not only does it have to ensure reliable protection against rain, cold and wind, but also against the additional risks of flame propagation and the danger posed by arc faults.
The sudden discharge of electrical energy in workplace situations can lead to severe burn injuries, or even the death of a worker. Inadvertent contact between an energised conductor and another conductor or an earthed surface causes a short circuit.¹ A large amount of electrical energy is released within milliseconds, with intense radiant heat being generated that can instantly burn the body and set fire to clothing. In addition, an arc flash can produce an explosive blast, deafening noises and a cloud of toxic particles. Appalling injuries can occur, including third degree burns or severe damage to limbs.
Health and Safety regulations are in place to minimise risks to workers but companies must be able to assess the possibility of arc flash incidents in order to prevent them and to protect their workers. Failure to do so can result in prosecution, compensation claims, loss of business and damage to valuable equipment. Nonetheless, eliminating incidents altogether is challenging. In the UK 2016/17 figures indicate eight fatalities arising from contact with electricity.² While an earlier study over seven years, showed over 56,000 electricity related accidents.³ The German Statutory Occupational Accident Insurance Fund responsible for the energy, textile, electronics and media sectors (BG ETEM) reported 3,463 electrical accidents, a rise of 50% in five years.
One of the problems associated with these accidents is the incorrect use of available PPE. Although protective work wear must meet health and safety requirements, it has generally felt heavy and inflexible, particularly when wet. In some cases this has led to workers either not wearing it or wearing it incorrectly. According to an investigation by the Swiss Supervisory Authority ESTI (Federal Inspectorate for Heavy Current Installations), 14 percent of serious injuries from arc fault accidents result from a lack of proper protective gear.
Developments in PPE
Although such incidents are rare, companies are required by law to protect their engineers by procuring protective workwear with arc retardant properties. An ideal solution to this need is a garment that would balance wearer comfort with full protection. It would need to be durable enough for working conditions and be waterproof, windproof, flexible and lightweight as well.
The recent introduction of lightweight arc-rated GORE-TEX® Heat and Flame garments with Gore Pyrad Fabric Technology offers something brand new to the market. Other PPE garments tend to use a cotton/mod-acrylic textile, that is heavy and uncomfortable when wet, but this new technology blocks convective heat flow, particularly during arc exposure and stops flame propagation by forming a carbonaceous char with the textile. This is effective in reducing heat transfer to skin. Garments engineered utilising this fabric are certified according to European Standard EN 61482-1-2 class 2 for arc risk, EN ISO 11612 for flame, and are anti-static compliant.
All new products need to be tested and feedback from recent trials with leading utility companies has provided a positive response from wearers. Currently 14 manufacturers from eight European countries have confirmed the daily performance of this technology incorporated in protective clothing. Here in the UK Scottish and Southern Electricity engineers tested outerwear by Bell Apparel featuring the new technology and weighing 45% less than other products. All users reported that the jacket was pleasantly cool or sufficiently warm for the relevant conditions. Three quarters of testers found the garments soft and flexible, with 50% of users saying that the jackets were dry in a few hours with the remaining 50% reporting it dry by the next day or next use.
Preventing arc flash and other electrical incidents remains a challenge, but developments in PPE have been shown to lead to greater user acceptability and therefore more correct usage.
Gordon Burns is European application engineer at W. L. Gore and Associates UK Limited. For more information visit, www.gore.co.uk