Complete guide to fire classification, ASTM testing standards, global manufacturers, temperature behavior, and cost analysis.
Fire-rated glass is classified by how it protects against the spread of fire, smoke, and heat. The two primary classifications are EW (Integrity + Radiation Control) and EI (Integrity + Insulation).
EW (Etanche aux flammes + rayonnement limité) glass maintains the integrity of the barrier against flames and smoke while limiting radiant heat to a maximum of 15 kW/m² on the unexposed side.
EI (Etanche + Isolant) glass provides full fire compartmentalization — it maintains integrity and limits heat transfer so that the unexposed face temperature rise does not exceed 140°C average / 180°C maximum above ambient.
Side-by-side technical, performance, and commercial comparison of both glass types.
| Parameter | EW Glass | EI Glass | Better Option |
|---|---|---|---|
| Full Name | Integrity + Radiation Control | Integrity + Insulation | — |
| Flame Barrier | Yes | Yes | Equal |
| Smoke Barrier | Yes | Yes | Equal |
| Radiant Heat Control | Limited ≤15 kW/m² | Full insulation | EI |
| Unexposed Face Temp | Can exceed 300–500°C | Max +140°C above ambient | EI |
| Conductive Heat | Not controlled | Controlled | EI |
| Glass Construction | Monolithic / toughened / wired | Multi-layer intumescent laminate | EI (performance) |
| Intumescent Interlayer | Optional / thin | Essential — thick gel/laminate | — |
| Transparency / Clarity | High clarity | Slightly reduced clarity | EW |
| Weight | Lighter | Heavier (multiple layers) | EW |
| Thickness Range | 6–25 mm | 20–65 mm+ | EW |
| Typical Cost/m² | USD 200–500 | USD 400–1,200 | EW (cost) |
| Cost-Benefit Ratio | High — good for facades | Medium — necessary for safety | EW where permitted |
| Installation Complexity | Standard frames work | Requires special load-bearing frames | EW |
| Usable for Evacuation Routes | Typically No | Yes — code required | EI |
| Large Facade Use | Ideal | Possible but expensive | EW |
| Suitable for Hospitals/Schools | Partial | Strongly recommended | EI |
| Common Ratings | EW 30 / 60 / 90 / 120 | EI 30 / 60 / 90 / 120 / 180 | — |
| European Standard | EN 13501-2 | EN 13501-2 | — |
| Overall Safety Level | Moderate-High | Highest | EI |
The American Society for Testing and Materials (ASTM) defines the test procedures that determine a glass assembly's fire rating. Multiple ASTM standards apply, each covering different aspects.
The primary fire endurance test. Specimens are exposed to a standardized time-temperature curve. Tests for structural integrity, heat transmission, and flame passage. Ratings: 30, 45, 60, 90, 120, 180, 240 min.
Specifically governs window, glazing, and door lite assemblies. Tests for integrity under the E119 temperature curve. The basis for fire-rated glass product listings in the US.
Tests penetrations through fire-rated assemblies. Relevant when glazed assemblies are embedded in walls or floors. Determines F-rating (flame) and T-rating (temperature).
Tests window assemblies under positive pressure differential, simulating real stack-effect conditions in high-rise buildings. More stringent than E163.
Fire door testing including glazed sidelites and transoms under positive pressure. Used for glass inserts in fire-rated door assemblies.
Defines types of heat-treated, tempered, and wired glass. C1115 covers dense pressed ceramics used in fire-rated glazing. Referenced by manufacturers for base material qualification.
Full-size representative assembly (glass + frame + seals) is installed into a test furnace opening per exact field conditions.
Gas furnace ignited. Temperature follows the ASTM E119 time-temperature curve: 538°C at 5 min → 927°C at 1 hr → 1010°C at 2 hrs.
Thermocouples on unexposed face record temperatures every 1 min. Integrity observed visually and via cotton pad test for hot gases.
After fire exposure, assembly is immediately subjected to a hose stream (2.5 bar) to simulate firefighting impact loads and thermal shock.
Rating is the time (minutes) the assembly withstood before any failure criterion was met. This becomes the labeled fire rating.
| Standard Body | Standard | Region | Test Curve | Key Glass Criteria | Notation |
|---|---|---|---|---|---|
| ASTM | E119 / E163 | USA | ASTM E119 curve | Integrity (no flame passage), Temperature (T-rating), Hose stream | W (integrity only) / WX (extended) |
| CEN | EN 1363-1 / EN 13501-2 | Europe / UAE / India | ISO 834 standard fire curve | E (integrity), EW (integrity+radiation), EI (integrity+insulation) | EI 30/60/90/120 |
| BS | BS 476 Part 22 | UK / Ex-Commonwealth | BS 476 curve (similar to ISO 834) | Integrity, Insulation. "Fire Check" and "Fire Resisting" designations | FD (fire door), E, EI |
| AS/NZS | AS 1530.4 / AS 4072 | Australia / NZ | ISO 834 equivalent | Integrity (I), Insulation (–I), Structural Adequacy (–/–/–) | -/60/60 (format: S/I/I) |
| GB | GB 15763.1 / GB/T 12513 | China | ISO 834 | A-class (EI equiv.), B-class (EW equiv.), C-class (E only) | A60, B60, C60 |
| IS | IS 3809 / NBC 2016 | India | BS 476 / ISO 834 hybrid | Integrity and insulation per NBC. EI class referenced in recent codes | EI / E classification |
| UL | UL 9 / UL 10B/10C | USA / Canada | ASTM E119 equivalent | Used for listing fire-rated glass products; fire door glass inserts | UL-Listed rating minutes |
Simulate how temperature increases on both sides of EW and EI glass under the standard fire curve. Adjust fire intensity, exposure time, and glass type.
Leading manufacturers of EW and EI certified fire-rated glazing systems across key regions.
| Country / Region | Primary Standard | EW Equivalent | EI Equivalent | Common Ratings Used | Testing Body | Mandatory in |
|---|---|---|---|---|---|---|
| 🇪🇺 European Union | EN 13501-2 / EN 1364-3/4 | EW | EI | EI 30, EI 60, EI 90, EI 120, EI 180 | Notified Bodies (CE Mark) | Escape routes, hospitals, high-rise |
| 🇬🇧 United Kingdom | BS 476 Pt 22 + EN 13501-2 | EW | EI | EI 30, EI 60, EI 90 | BRE, Warrington, Exova | Approved Doc B (Building Regs) |
| 🇺🇸 United States | ASTM E119 / E163 / UL 9 | W (integrity, ≤15 kW/m² via NFPA) | WH (W + temperature rise ≤163°C) | 20/45/60/90/180 min | UL, ITS, Intertek | IBC, IFC, NFPA 101 |
| 🇦🇪 UAE / GCC | UAE Fire & Life Safety Code (NFPA base) + EN | EW | EI | EI 30, EI 60, EI 90, EI 120 | Civil Defence (Dubai, Abu Dhabi) | All commercial, high-rise, public buildings |
| 🇮🇳 India | NBC 2016 / IS 3809 / IS 1641 | Type B / C glass (partial) | Type A (EI equiv.) per NBC | 30, 60, 90 min | NABL-accredited labs, BIS | NBC mandatory for Group A,B,C occupancies |
| 🇦🇺 Australia / NZ | AS 1530.4 / NCC (BCA) | –/60/– (Integrity only with radiation limit) | –/60/60 (Integrity + Insulation) | 30, 60, 90, 120 min | CSIRO, Warrington Fire (AU) | BCA Class 2–9 buildings |
| 🇨🇳 China | GB 15763.1 / GB/T 12513 | B Class | A Class | A30, A60, A90, B30, B60 | MPS-certified labs | GB50016 (Fire Code) — commercial, public |
| 🇯🇵 Japan | Building Standard Law / JIS A 1301 | Quasi-fire resistant (準耐火) | Fire resistant (耐火) | 20, 45, 60 min | BCJ, UR Urban Renaissance Agency | Class 1 / 2 fire-resistant buildings |
| 🇸🇬 Singapore | SS 332 / SCDF Code | EW | EI | EI 30, EI 60, EI 90 | SCDF approved labs | All fire compartment walls, means of escape |
| 🇩🇿🇿🇦 Africa (varies) | SANS / EN (South Africa); varies | EN-equivalent EW | EN-equivalent EI | 30, 60, 90 min | SABS (SA), local fire authorities | High-rise, healthcare, public assembly |
| Product | Manufacturer | Type | Max Rating | Thickness | Transparency | Certifications | Best For |
|---|---|---|---|---|---|---|---|
| Pyrobel® | AGC Glass Europe | EI | EI 120 | 16–52 mm | High | CE, EN 13501-2 | Facades, partitions, doors |
| Contraflam® Light | VETROTECH / Saint-Gobain | EI | EI 120 | 22–56 mm | Very High | CE, UL, ULC | Design facades, atria |
| Contraflam® Structure | VETROTECH / Saint-Gobain | EI | EI 120 | 32–72 mm | High | CE, EN, ETA | Structural glass walls |
| Pyrostop® | Pilkington (NSG Group) | EI | EI 120 | 28–62 mm | High | CE, BS, EN | Partitions, stairwells |
| Pyroshield® | Pilkington (NSG Group) | EW | EW 60 | 7 mm | Clear/wired | BS 476, EN | Large openings, wire glass legacy |
| Pyrodur® | Pilkington (NSG Group) | EW | EW 30 | 5–7 mm | Moderate (patterned) | EN 13501-2 | Low-cost fire protection, internal doors |
| FireLite® | Technical Glass / PROMAT | EW | EW 60 | 6.4–12.7 mm | Very High (ceramic) | UL 9, ASTM E163 | US market, vision panels |
| FireLite® NT | Technical Glass Products | EI | EI 90 | 38 mm | High | UL 10B/C, ASTM E119 | US fire door inserts |
| PolFlam® W/EI | Schollglas | EI | EI 120 | 30–68 mm | High | CE, EN 13501-2 | Large facade elements |
| Guardian FireGuard™ | Guardian Glass | EI/EW | EI 60 | 20–45 mm | High | EN, UL, UAE Civil Defence | GCC commercial buildings |
| AIS FireLite | Asahi India Glass | EI | EI 60 | 18–38 mm | High | NBC India, IS 3809 | Indian commercial / infrastructure |
Cost is a primary constraint and the building code permits it for the specific application. EW offers excellent cost-to-benefit ratio for large glazed facades, atriums, and external curtain walls where occupants won't be immediately adjacent.
Life safety is paramount or code mandates full insulation. EI is required where people may be sheltering behind the glass, evacuating nearby, or where healthcare and educational occupancies demand the highest protection standard.
EW glass typically costs 30–50% less than equivalent EI glass. For a project where code permits EW, specifying EI represents unnecessary expenditure. However, where EI is code-mandated, the liability cost of non-compliance and life-safety risk dwarfs the material cost difference. In mixed-use high-rise projects, a pragmatic approach is: EI for circulation/escape paths, EW for occupied office facades.