When selecting FR (flame-resistant) rain gear, it’s essential to understand key terms to make informed decisions. Here are 10 important terms to know:
- Flame Resistant (FR): The property of a material whereby ﬂaming combustion is prevented, terminated, or inhibited following application of a ﬂaming or non-ﬂaming source of ignition, with or without subsequent removal of the ignition source. Which means materials that resist ignition, self-extinguish, maintain their integrity and not melt or drip when exposed to flames or high temperatures.
- Arc Flash: A sudden release of electrical energy that occurs when a high-voltage current jumps through the air between conductors, producing intense heat, pressure waves, and bright flashes of light.
- Flash Fire: A sudden, intense fire caused by the ignition of a mixture of air and a dispersed flammable substance, such as a flammable liquid or gas.
- NFPA 70E: A safety standard from the National Fire Protection Association (NFPA) that addresses electrical safety requirements for employees and focuses on protecting workers from arc flash hazards associated with electrical installations.
- NFPA 2112: A safety standard from the NFPA that specifies the minimum design, performance, certification, and testing requirements for flame-resistant garments for use in areas at risk of flash fires.
- ASTM F1891: A safety specification from the American Society for Testing and Materials (ASTM) that establishes applicable test methods, minimum physical and thermal performance criteria, a suggested sizing guide, and suggested purchasing information for rainwear for use by workers who may be exposed to thermal
hazards of momentary electric arcs and open ﬂames.
- ASTM F2733: This speciﬁcation establishes applicable test methods, minimum physical and thermal performance criteria, a suggested sizing guide, and suggested purchasing information for rainwear for use by workers who are potentially exposed to industrial hydrocarbon ﬁres or other petrochemical ﬁre hazards.
- Arc Rating: A value that describes the protective performance of FR fabrics against arc flashes, expressed in calories per square centimeter (cal/cm²). Specifically, it is the amount of energy where there is a 50% probability of a second-degree burn on human tissue. Generally, higher arc ratings indicate better protection.
- Break-open: The point at which a fabric’s structure is compromised due to exposure to an arc flash or flash fire, resulting in the formation of holes or tears that allows the wearer to be exposed to the thermal hazards.
- Inherent FR: Flame resistance that is an innate property of the fabric’s fibers, meaning it will not wash out or diminish over time.
- Treated FR: Flame resistance that is achieved by applying a chemical treatment to the fabric. The effectiveness of treated FR may decrease over time or with repeated laundering, so it’s essential to follow care instructions to maintain the fabric’s protective properties.
Understanding these terms will help you choose FR rain gear that meets your specific needs and provides adequate protection for your work environment.