Layering Arc Rated Apparel Any Better or Worse Than Arc Flash Suit Protection?
This common question deserves an explanation.
- By Rich Godjics
- Jun 01, 2022
The topic of layering arc-rated apparel and its protection in comparison to other protective apparel is often a hot topic of discussion. There is currently not an industry standard or requirement we can point to that guides us with a preferred method to protect the worker against incident energies in this range. In fact, the well-recognized NFPA 70E Arc-Flash PPE Category tables point to both layered arc-rated apparel or an arc-flash suit as acceptable options.
Factors That Drive Safety Decisions
For both the employer and worker, the process to making the safety decision on selecting arc-rated apparel and PPE involves various considerations including the following influencers: hazard level, frequency of hazardous work through the workday or project, number workers affected, cost and compliance-risk drivers such as wearer comfort and ease of use. What also matters in safety purchasing decisions and trends is what industry is asking the question and what arc rating level needed.
The U.S. electrical utility industry most commonly uses arc-rated apparel in single and multi-layered apparel combinations because of the varied hazard levels in the work done daily, and the ever-changing weather conditions and temperature that affect the industry. Their multi-layered clothing combinations approach arc ratings in the 13 to 25 cal/cm², but layering options diminish substantially when nearing 20 cal/cm² requirements. In other applications such as substation work, utilities commonly use 20 to 25 cal arc flash suit PPE rather than prescribing multi-layered arc-rated clothing combinations that achieve the same arc ratings. By comparison, other industries such as electrical contractors and industrial workers do not prefer layered arc rating combinations but use arc flash suits for most situations where incident energies exceed 12 cal/cm².
The U.S. market is very definitive when selecting arc-rated apparel for situations up to 8 to 12 cal and at or above 25-cal exposures. Where the question about the effectiveness and safety of layered clothing or requiring same level protection in arc flash suits is most routinely asked is for tasks where the incident energy ranges 13 to 25 cal/cm².
Next Level Innovation
For years, industrial companies have selected 8 to 12 cal arc rated shirts and pants and have not abandoned their original investment decisions to transition to arc-rated, task-based PPE kits for good reason. The on-going innovation in arc-rated protective fabric technologies continues to drive improved user comfort and conformity with lighter fabrics, that stretch, have a better appearance and quick-dry technologies that make daily wear apparel more acceptable than many of the best options available five to ten years ago.
This article originally appeared in the June 2022 issue of Occupational Health & Safety.