We’re breaking down the various tests in NFPA 2112 for flash fire protection. Now that we’ve taken a closer look at “the Manikin Test” (ASTM F1930) – the most well-known of the tests, we’re turning our attention to the other three main fabric tests in the standard.
Scott Margolin, Vice President of Technical, walks us through NFPA 2112’s pass/fail criteria for Vertical Flame (ASTM D6413), Heat Transfer Performance (ASTM F2700), and Thermal Shrinkage (ASTM F2894):
NFPA 2112 provides strict pass/fail criteria on each of these three (3) fabric tests to help identify flame resistant fabrics that meet the minimum performance properties necessary to be worn for flash fire protection.
1) Vertical Flame Test, ASTM D6413
NFPA 2112 requires a char length of 4” or less on the Vertical Flame Test (ASTM D6413), on a sample that has been laundered 100 times. Check out Episode 2 for a closer look at the vertical flame test.
Remember: ASTM provides test methods, but the pass/fail criteria applied to the test methods are most often found in other standards – in this case, NFPA 2112. Different standards (like ASTM F1506 on the arc flash side) can use the same test method, but have different requirements to pass.
2) Heat Transfer Performance (HTP), ASTM F2700
The HTP test measures a fabric’s ability to insulate the wearer from a second-degree burn.
To do this, it exposes a small piece of fabric to a steady heat source from below, while a thermocouple on top of the fabric measures the heat that passes through.
To pass NFPA 2112, a fabric must achieve a 3+ calorie rating when in contact, or 6+ calorie rating when spaced, by the time the sensor records a temperature which exceeds those causing second-degree burn.
3) The Oven Test (also known as the Thermal Shrinkage Test), ASTM F2894
This test is actually used to evaluate fabrics with respect to two requirements in NFPA 2112:
Each of these tests serves an important role in measuring a fabric’s response to heat under controlled conditions.
By using these tests together and in combination with several other tests, NFPA 2112 provides the backbone needed to ensure a fabric or garment combines all the features necessary to effectively protect a worker in the event of a flash fire.
In our next post, we’ll examine the other tests in NFPA 2112 that serve a lesser-known but important role in identifying flame resistant fabrics that can be worn for flash fire protection.