Historically, the flame resistant properties of FR fabrics could be separated into two categories: Inherent and treated. Once upon a time, this was a relevant distinction. It meant the difference between FR properties that were durable, and those that were not. However, these terms ceased to provide information to safety managers looking to evaluate FR fabrics way back in 1987.
The success of your flame resistant (FR) clothing program depends heavily on the fabric used to construct the garments. Both arc rating and flash fire “2112” testing are done by fabric brand and weight; the fabric brand is also the key factor in durability of FR properties, initial and long term comfort, shrinkage control, wear life, and more. For these reasons, it’s very important that you take an active role in specifying the fabric used to produce finished garments. Here are a few questions to consider when evaluating fabric manufacturers:
There are many questions and even more misunderstandings around comfort and heat stress for people specifying or wearing arc rated and flame resistant protective apparel; thus, it is important to understand a few basics on the interrelationship, if any, to garment or fabric type and weight. Discomfort and heat stress are not used interchangeably. Comfort is an inherently subjective characteristic that cannot be effectively or predictably measured by lab tests or judged across a desk, and is considered a nuisance issue. However, heat illness is a specific and potentially medically consequential event; it is unrelated to comfort, and is a potentially major health issue.
There’s a new acronym in the world of PPE, and it has been causing confusion, both among folks new to the subject as well as those long familiar with FR (Flame Resistant) clothing. The letters “AR” stand for Arc Rated, and made their debut in the recent revision of NFPA 70E; the short explanation of the difference is that ALL AR clothing is flame resistant (FR), but not all FR clothing has been Arc Rated.