ASTM E1623 Determination of Fire and Thermal Parameters of Materials, Products, and Systems Using an Intermediate Scale Calorimeter (ICAL)

Get Certified ASTM E1623 Testing for Reliable Fire Performance Data

Obtaining ASTM E1623 testing from an accredited fire testing laboratory helps manufacturers, engineers, and product developers demonstrate the fire performance of materials, products, and assemblies. Professional testing evaluates specimens in their end-use thickness and configuration under controlled radiant heat exposure. The assessment provides reliable data on heat release rate, ignition time, mass loss rate, smoke development, and gas release. A comprehensive test report documents specimen details, applied heat flux, ignition method, test conditions, measured parameters, and observed physical changes. Matestlabs offers professional ASTM E1623 testing services to support material evaluation, product development, fire safety engineering, regulatory documentation, and computer-based fire modeling requirements.

The scope of the test method includes:

• Test type: Fire-test-response method that uses an intermediate scale calorimeter (ICAL)
• Exposure: Constant radiant heat flux of 0 to 50 kW/m² on a vertical specimen, with or without an external ignitor
• Heat release: Determined by oxygen consumption calorimetry from the oxygen concentration and flow rate in the exhaust duct
• Smoke: Quantified by the obscuration of light by the combustion product stream in the exhaust duct
• Ignition: Hot wires ignite the combustible vapors during ignition and heat release tests, and line burners replace them for flame spread parameters
• Measured characteristics: Ignitability, heat release rates, mass loss rates, visible smoke development, and gas release under well-ventilated conditions
• Model inputs: Effective heat of combustion, surface temperature, ignition temperature, and emissivity for computer fire models
• Specimens: Materials, products, and assemblies tested in thicknesses and configurations that represent actual end use
• Units: SI values are standard
• Limits: The standard does not by itself include all factors needed for fire hazard or fire risk assessment

What are the Uses of This Test Method?

The method gives manufacturers, designers, and researchers a way to measure how materials and assemblies respond to radiant heat. The uses include:

• Determines the heat release rate of materials, products, and assemblies.
• Measures the time to ignition, the mass loss rate, and smoke and gas production.
• Assesses the heat release rate of a wall assembly at its end-use thickness.
• Provides effective heat of combustion, surface temperature, ignition temperature, and emissivity as inputs for computer fire models.
• Supports flame spread studies when technicians use line burners in place of hot wire igniters.
• Supports evaluation, design, and research and development of materials, products, and assemblies.

What Materials Can Be Tested Under ASTM E1623?

The method applies to materials, products, and assemblies, such as wall assemblies, that technicians can test at their end-use thickness. A specimen includes the representative joints and other details when they are part of normal design. The method also applies to end-use products that do not have a flat surface, and technicians adjust the heat flux to the value wanted at the average distance of the surface from the radiant panel. Results have limited validity if the specimen melts enough to overflow the drip tray or if explosive spalling occurs.

Why is ASTM E1623 Important?

Fire behavior depends on thickness, layering, and joints, so a small coupon does not always show how a whole assembly burns. The method tests assemblies in their end-use configuration and measures heat release through oxygen consumption, providing engineers with data for fire modeling. These evaluations complement broader fire resistance testing used to assess the performance of construction materials and assemblies. The standard also emphasizes that results apply only to the exposure conditions used during testing.

ASTM E1623 Testing Process and Data Collection

The technicians start testing by mounting the specimen in its end-use configuration and mounting it vertically. They adjust the heat flux, start the exposure, and start the hot wire to ignite the vapors. During the test, all instruments monitor the oxygen concentration, the exhaust flow rate, the light obscuration, and the mass of the specimen. The technicians also record ignition, flaming, and any sagging, melting, or spalling. Based on the recorded data, the laboratory calculates heat release rate, time to ignition, mass loss rate, and smoke development.

Common Challenges and Troubleshooting

Specimen behavior causes most of the trouble. A specimen that melts enough to overflow the drip tray, or one that suffers explosive spalling, gives results of limited validity. Specimens that sag, deform, or delaminate also need careful interpretation, so technicians report what they see. Heat release measurements at low heat flux, below 10 kW/m², need special considerations. A non-flat surface changes the heat flux the surface receives, so technicians adjust the setting for the average distance from the radiant panel. Results hold only for the exposure conditions of the test, so a change in heat flux or configuration can change the outcome. Fire testing is also hazardous, and laboratories use safeguards for personnel and property.

• The laboratory reports the heat release rate calculated through oxygen consumption calorimetry and records the smoke development and mass loss for each specimen tested.
• Technicians document the specimen configuration, applied heat flux, ignition method, exposure conditions, and test duration to support accurate review and reproducibility.
• Analysts examine the recorded data and specimen behavior, noting flaming, deformation, sagging, delamination, melting, or explosive spalling.
• Engineers interpret the results to understand fire performance under the specific test conditions and identify relevant inputs for computer fire models.
• Manufacturers and designers use these findings to compare materials, evaluate product performance, and support fire safety engineering decisions.

Link to ASTM E1623 Standard