When looking for FR clothing, one can’t help but wonder how FR clothes are tested to determine what is fire resistant and what isn’t. Making things more complicated are the bevy of regulatory agencies overseeing each industry needing the protection provided by FR clothing.
Although there seems to be a lot involved, testing FR garments is a straight forward process involving a variety of different test methods, some of which are also outlined in this video from our YouTube site.
1. Flammability – Whether or not a fabric can be considered flame-resistant is determined by the vertical flame test, ASTM D6413 Flame resistance of Textiles. This test meets all requirements for flammability resistance set forth by the NFPA and ASTM.
In testing flammability, a piece of fabric is held to a burner for 12 seconds and examined for char length and after flame. The amount of char and duration of flame after the fabric is removed from the burner determine whether or not the fabric is FR-compliant to a particular standard. Different standards have different requirements.
2. Arc Rating – All FR fabrics sold for electric arc flash protection, must go through an arc rating test to determine its arc rating, as required by ASTM F1506, NFPA 70E, NESC, and OSHA 1910.269. The test to determine arc rating is ASTM F1959, where a piece of fabric is exposed to an arc flash while sensors determine how it performed. The tested fabric would have either an Arc Thermal Performance Value (ATPV), or Energy Breakopen Threshold (EBT).
3. Flash Fire Manikin Test – Fabrics sold for flash fire protection are tested by ASTM F1930. The fabric in the form of a coverall is exposed to multiple flames (not a flash fire, but generating a specific amount of thermal energy). The Flash Fire Manikin test is famous to anyone working in the industry because it’s when a manikin is dressed in the FR coverall and exposed to the flames for three seconds to predict the percentage of second and third degree body burn levels possible all over the body.
4. Heat Transfer Performance Test – ASTM F2700 exposes fabric to a combination of radiant and conductive heat to test how much heat transfers through the fabric over time. Understanding how long a garment can withstand high heat exposure is important to understanding what hazards it can protect against.
5. Heat Resistance and Thermal Shrinkage Test – Some standards also require fabrics to be tested for heat and thermal shrinkage. This is often referred to as the oven test. The fabric sample is placed in an oven at 500° for typically 5 minutes and it must not ignite, melt and drip, separate and shrink more than 10%.
Although the regulations can seem overwhelming, testing clothing for flame-resistance is a common practice for the legitimate fabric suppliers in the industry. Because these are safety garments you want a garment that won’t ignite and continue to burn, causing potentially fatal severe skin burn injuries. Wearing the appropriate FR clothing can help protect your workers in hazardous situations.