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Short answer
ASTM E119 is the standard test method for fire tests of building construction and materials. It measures how long a wall, partition, floor, roof, column or beam assembly can contain a fire, keep carrying its load, or both, when exposed to a set fire. The result is a rating in hours, such as one hour or two hours, that applies to the assembly as tested.
Definition and scope
ASTM E119 is titled Standard Test Methods for Fire Tests of Building Construction and Materials. According to its ASTM scope, it covers masonry unit assemblies and composite assemblies of structural materials, including loadbearing and other walls, partitions, columns, girders, beams, and floor and roof slabs. Its stated significance is to measure how long such elements contain a fire, retain structural integrity, or both, under a prescribed fire exposure. ASTM lists E119-26 as the active edition; the scope text summarized here is from E119-20, so confirm which edition a specification cites.
The standard classifies an assembly. It does not rate a single product in isolation, and ASTM states in section 1.2 that classifications shall not be construed as having determined suitability under other conditions.
How the test works in practice
A specimen is built to represent the construction and exposed to fire in a furnace. Testing laboratory Intertek describes the furnace as following a prescribed time-temperature curve; it also explains that performance is the time that passes before the first critical failure, whether that is a temperature rise on the unexposed side, flame or hot-gas projection through the assembly, or loss of the applied load.
What is measured depends on the element, per the ASTM scope:
- Walls, partitions, floors and roofs: heat transmission, hot-gas transmission and, for loadbearing assemblies, load-carrying ability.
- Beams and columns: load-carrying ability, taking account of restrained or unrestrained ends.
When a hose stream test is required, it follows the fire exposure and is carried out under ASTM Practice E2226. Intertek notes it is usually applied to wall assemblies and may be run on a duplicate sample. Results are reported as hours, for example 1/2-h, 2-h or 6-h, in the test report and in design listings.
Test requirements by element
The ICC-ES summary of E119 gives these specimen sizes and criteria. Treat them as that body’s summary and check the current edition of the standard for the controlling text.
| Element | Minimum exposed size (ICC-ES summary) | Edge and load conditions or criteria noted |
|---|---|---|
| Loadbearing wall or partition | At least 100 ft² exposed, neither dimension under 9 ft | Vertical edges not restrained; must carry the load, not ignite cotton waste, and pass the hose stream |
| Non-loadbearing wall or partition | Same size as above | Restrained on all four edges |
| Column | At least 9 ft exposed | – |
| Floor or roof | At least 180 ft² exposed, neither dimension under 12 ft | Unexposed-surface temperature rise limit of 250°F (139°C) above the initial temperature |
For protective membranes, the same summary treats an average thermocouple rise above 250°F, or any single reading above 325°F, over the initial temperature as failure.
What an E119 rating does not tell you
Section 4.4 of the standard lists what the test does not evaluate. The NZ Building Code Hub summary of E119-20 repeats the main limits. Use this as a checklist when a specification or product sheet cites E119:
- Smoke and toxic gas: generation of smoke or toxic gases, and control of smoke passage, are not measured.
- Surface flame spread: not measured. That is a different question from fire resistance.
- Joints: fire behaviour of joints such as floor-to-wall and wall-to-wall is not evaluated.
- Openings and penetrations: the effect of conventional openings such as outlets and plumbing penetrations is not included unless they were part of the tested construction.
- Other lengths and components: performance of components or lengths other than those tested is not covered, and results are not directly applicable to different materials.
The NZ Building Code Hub also notes that the test does not by itself cover all factors of fire hazard or fire risk assessment, and Intertek describes results as a relative comparison of similar building elements.
Where it matters for labs and clinics
Laboratories and clinical buildings contain many wall, floor and corridor assemblies that are specified by fire-resistance hours, and many of them are pierced by utilities: outlets, plumbing and similar services. The limits above are the practical gaps for facilities staff. A rated assembly in a drawing or listing describes the construction that was tested; whether a particular penetration or joint is covered depends on what the listing includes. When a project cites E119, useful questions to put to the designer or supplier are which tested assembly is meant, which edition applies, and whether the penetrations and joints in question are part of the tested construction.
Fire-resistance ratings sit alongside other safety rules for these buildings. For the wider framework, see CASRAI’s guides to the NFPA 101 Life Safety Code and the NFPA 99 Health Care Facilities Code. For storage hazards in the same spaces, see flammable liquid storage cabinet requirements and compressed gas cylinder storage requirements.
Common misunderstandings
- “Fire-rated” means fireproof. A rating is a time under a defined test exposure, not a guarantee beyond that exposure.
- A rating covers the whole wall system. It covers the tested assembly; joints and penetrations are outside the test unless they were included.
- A rating says something about smoke. Smoke generation and smoke passage are not measured by E119.
- The rating transfers to any size or material. ASTM states the classification does not determine suitability under other conditions.
- E119 is the only equivalent. The NZ Building Code Hub describes ASTM E119-20 as similar to UL 263.
Sources
- ASTM International, E119 store page (scope, significance, section 1.2 and 4.4 limits), store.astm.org/e0119-20.html, checked 2026-10-29.
- ICC Evaluation Service, E119 overview (specimen sizes and criteria), icc-es.org, checked 2026-10-29.
- Intertek, ASTM E119 testing page, intertek.com/building/standards/astm-e119, checked 2026-10-29.
- New Zealand Building Code Hub, ASTM E119-20, codehub.building.govt.nz, checked 2026-10-29.
