The Origins of ASTM E84

One of the most widely accepted fire testing methods is ASTM E84, also commonly referred to as the "tunnel test." It’s used to evaluate the flame spread characteristics of surface materials along with the smoke produced by combustion.

What Is ASTM E84?

ASTM E84, also known as the "Standard Test Method for Surface Burning Characteristics of Building Materials," is a widely recognized testing standard developed by ASTM International.

This standard assesses the comparative surface burning characteristics of various building materials to determine their flame spread and smoke-developed indices.

The results obtained through ASTM E84 testing provide valuable information about the fire performance of materials, helping architects, engineers, and regulatory authorities make informed decisions regarding the safety and compliance of construction materials.

The test involves exposing a material to controlled flame conditions and measuring its surface burning behavior, contributing to the development and enforcement of fire safety standards in the construction industry.

Corresponding test standards include UL 723.

History of ASTM E84

ASTM E84 was introduced around 1922 to evaluate "whitewash" coatings that were being heavily promoted at the time. Currently, the method is used on virtually all surface materials used in buildings and other structures that require acceptance from national code bodies.

In the tragic 1942 Boston Coconut Grove nightclub fire and the more recent Station nightclub fire in Rhode Island in 2003, which killed 100 and injured 230, it was noted that both exhibited the same type of flame spread escalation that is attempted to be evaluated in the tunnel test.

This demonstrates how extremely important the test is for protecting life safety.

ASTM E84 Testing Procedures

ASTM E84 testing procedures involve several key steps. Initial preparations include obtaining representative specimens and conditioning them appropriately. Types of test specimens may include building materials, coatings, insulation, finishes, fabrics, and other surfaces requiring classification.

The test apparatus is then set up, featuring a controlled environment with an ignition source. At NGC Testing Services, we conduct the ASTM E84 flame spread test using our on-site Steiner tunnel furnace.

Specimens, prepared to standard dimensions and methods, are exposed to a controlled air flow and flaming fire exposure, and parameters such as flame spread distance, ignition time, and smoke development are meticulously recorded. The Flame Spread Index (FSI) and Smoke-Developed Index (SDI) are calculated based on this data.

The results, along with any necessary observations, are reported to determine the material's compliance with fire safety standards.

Repeat testing may be necessary in certain cases, emphasizing the importance of closely following the standard's guidelines for accurate and reliable evaluations of building material fire performance.

The Steiner Tunnel

The tunnel used in ASTM E84 testing has been designated the "Steiner Tunnel" after Albert J. Steiner, an engineer who had spent much time developing this and other fire test methods.

The 1.5-ft.-by-25-ft. horizontal tunnel is a closely controlled environment to ensure repeatable test results. Red oak, heptane, and cement board are utilized as reference standards in its calibration.

Create Safer Built Environments With Full-Scale Fire Testing

ASTM E84 stands as a pivotal standard in ensuring the fire safety of building materials, offering a standardized evaluation of surface burning characteristics. The standard not only aids in regulatory compliance but also empowers architects, engineers, and industry professionals to make informed decisions about material selection.

If you’re interested in learning more about ASTM E84 or other testing methods, connect with a fire test expert at NGC Testing Services today.

This post was originally published in September 2021 by Bob Menchetti and was updated and republished in January 2024.