Flammability Testing Services
Fire Technology Services

image: Exceeding clients' expectations by providing world-class, innovative fire research, testing and product certification services

Exceeding clients' expectations by providing world-class, innovative fire research, testing and product certification services

image: Close-up view of a cone calorimeter test

Close-up view of a cone calorimeter test

image: Cone calorimeter test in progress

Cone calorimeter test in progress

Standardized and custom material flammability tests are performed by Southwest Research Institute (SwRI) for industry and government clients. SwRI has the expertise and facilities to perform heat release rate calorimetry in small-, intermediate- and industrial-scale applications. Rate of heat release quantifies the energy generated by a fire and is measured using the principles of oxygen consumption calorimetry. Typical flammability tests and procedures are discussed below.

Small-Scale Calorimetry Applications

Cone Calorimeter

Cone calorimeter tests (ASTM E1354, ISO 5660, NFPA 271) measure heat release rate, mass loss rate and smoke production rate. Tests on 100-mm2 samples include:

  • Controlled levels of radiant heat (0–100 kW/m2) with or without external igniter
  • Heat flux from 0 to 100 kW/m2
  • Horizontal or vertical orientation

Bomb Calorimeter

Bomb calorimeter tests (ISO 1716, NFPA 259) measure heat of combustion in BTU/lb. Testing on 1-g pellets is conducted in standardized burn conditions at constant volume in an oxygen atmosphere. Tests include:

  • ISO 1716

    Combustion heat calculated on temperature rise, heat loss and latent heat of water vaporization
  • NFPA 259

    Similar test procedure combined with muffle furnace procedure to account for residue heat of combustion

Microcalorimeter Test

In the FAA microflow calorimeter test (ASTM D7309), a 5-mg specimen is decomposed under standardized conditions. Testing is conducted at a constant heating rate between 0.2 and 2 K/s in an oxygen-free environment. Calculations include:

  • Method A

    Controlled thermal decomposition, pyrolysis residue, specific heat of combustion, and heat release capacity
  • Method B

    Controlled thermal oxidative decomposition, combustion residue, and net calorific value

Industrial-Scale Calorimetry Applications

SwRI’s industrial-scale calorimeter is contained within a 5,000-ft2 test facility designed specifically for industrial-scale fire performance investigations. This calorimeter is used for testing of:

  • Vehicles
  • Commodities
  • Pool fires
  • Custom fire performance

Heat release rates up to 10 MW can be measured and exhaust flows up to 14 m3/s can be developed during testing.

Intermediate-Scale Calorimetry Applications

Room Corner Tests

Room corner tests (NFPA 286, NFPA 265, ISO 9705, UBC 8-2, UBC 26-3, UL 1715) evaluate the flammability of surface finishes on exposed interior walls and ceilings. Common measurements include:

  • Heat release rate
  • Smoke release rate
  • Heat flux
  • Gas temperature

A 768-ft3 test room is situated next to a 10-ft2 exhaust hood equipped to measure heat release rates up to 3 MW and deliver exhaust flow up to 4 m3/s.

Single Burning Item

The single burning item test (SBI – EN 13823) is used by the European Union to classify construction products, excluding floorings. Heat release rate and smoke growth rate are calculated to determine classifications.

SwRI works with European labs to perform testing in accordance with SBI and other European standards for clients wishing to obtain a European classification and CE mark.


CPSC 16 CFR, Part 1633, developed by the Consumer Product Safety Commission, addresses measurement of the flammability of mattresses, futons and mattress/box spring sets. SwRI can also run the following types of furniture tests:

  • California Technical Bulletin
  • Cigarette ignition
  • Open flame ignition
image: Non-compliant mattress/foundation set; peak heat release rate ~1 MW

Non-compliant mattress/foundation set; peak heat release rate ~1 MW

Flame Spread

  • ASTM E84 (NFPA 255, Steiner Tunnel Test)

    Standard Test Method for Surface Burning Characteristics of Building Materials
  • ASTM E162

    Standard Test Method for Surface Flammability of Materials Using a Radiant Heat Energy Source
  • ASTM E648 (NFPA 253)

    Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source
  • ASTM E1317 (IMO FTP Code Part 5)

    Standard Test Method for Flammability of Marine Surface Finishes

Smoke Density & Toxicity Testing

Fourier Transform Infrared (FTIR) Spectroscopy Technique

Fourier transform infrared (FTIR) spectroscopy is routinely used by SwRI staff to analyze effluents from fire tests and is the leading contract research and testing laboratory in the United States for fire smoke toxicity.

Other Standardized Testing Techniques

Our staff actively participates in ASTM and ISO committee meetings involving smoke toxicity to remain in the forefront of this field. We have access to other analytical techniques, such Gas Chromatography (GC) and Mass Spectrometry (MS).

Custom Fire Performance Evaluations

In addition to the standardized testing, our staff has the skills and capabilities to develop and perform custom fire performance evaluations based on the needs of our client. Currently our heat release rate facility has two 10 x 10-ft exhaust hoods capable of up to 3 MW fires, and one 20 x 20-ft exhaust hood capable of up to 10 MW fires.

Related Terminology

code compliance  •  engineering design  •  fire and explosion investigations  •  fire resistance  •  fire testing laboratory  •  material flammability  •  product development  •  risk and hazards  •  suppression  •  third-party certification  •  listing and labeling

Benefiting government, industry and the public through innovative science and technology
Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 9 technical divisions.