Views: 5758 Author: Site Editor Publish Time: 2026-07-23 Origin: Site
When specifying fire-rated glass for modern architectural projects, visual transparency is only half the story. The key to life safety lies in understanding how the glass responds when exposed to intense heat and flames.
If you've encountered ratings like E30, EW60, or EI120, you might wonder what these letters mean and why choosing the correct classification is so critical.
This guide will break down the European Standard (EN 13501-2) ratings, explain the difference between Integrity (E) and Insulation (I), and help you specify the right fire-rated glass for your next project.
Under European standards, fire resistance performance is measured by three primary criteria: Integrity (E), Radiation Control (W), and Insulation (I).
What it means: The glass acts as a physical barrier to keep flames and toxic gases from passing through to the non-fire side.
Pass criteria: No continuous flaming and no gaps/cracks that allow flames or smoke to penetrate during the tested period.
In simple terms: It keeps the fire contained, but it does not block heat transfer. High thermal radiation will still pass through the glass.
What it means: In addition to blocking flames and smoke, EW-rated glass limits the amount of radiant heat emitted through the glass.
Pass criteria: Radiant heat on the non-fire side stays below 15 kw/m² during the specified time.
In simple terms: It prevents nearby combustible materials on the safe side from spontaneously igniting due to intense heat radiation.
What it means: EI provides complete containment. It blocks flames, smoke, radiant heat, and direct thermal conduction.
Pass criteria: The average temperature rise on the unexposed (safe) side must not exceed 140℃ above initial room temperature (with no single point exceeding 180℃).
In simple terms: Even if temperatures on the fire side reach 1000℃, the safe side remains cool enough to touch or stand next to safely.
Rating Class | Flame & Smoke Barrier (Integrity) | Heat Radiation Control | Thermal Insulation (Touch-Safe) | Typical Applications |
Class E | ✅ | ❌ | ❌ | Exterior windows with wide spatial separation, lower-risk areas |
Class EW | ✅ | ✅ | ❌ | Escape corridors, facades close to adjacent properties |
Class EI | ✅ | ✅ | ✅ | Escape stairwells, fire compartment walls, hospitals, airports |
The numbers following the letters indicate the duration in minutes for which the glass maintains its performance during a standard fire test.
30 Minutes (e.g., EI30): Suitable for internal doors and basic compartmentation where fast evacuation is possible.
60 Minutes (e.g., EI60): The industry standard for commercial exit corridors, stairwells, and mid-rise building partitions.
90–120 Minutes (e.g., EI90 / EI120): Required for high-risk zones, high-rise buildings, underground transit hubs, data centers, and critical escape routes.
Unlike standard monolithic tempered or laminated glass (which shatters or transfers heat rapidly under extreme thermal stress), Class EI Fire-Rated Glass relies on advanced multi-layer technology:
Multi-layer Laminate: The glass consists of multiple toughened glass panes separated by clear, intumescent interlayers.
Thermal Reaction: When exposed to fire (around 120℃), the outer pane holds the flame, while the intumescent interlayer begins to react.
Foam Shield: The interlayer swells up into a thick, tough, opaque thermal foam shield.
Complete Blockage: This opaque shield absorbs the heat energy, keeping the non-fire side safe, cool, and calm during evacuation.
Choosing between E, EW, and EI ratings depends on building regulations, occupant evacuation time, and room layout:
Choose Class E if local codes only require preventing fire spread between non-critical outdoor areas.
Choose Class EW if you need to protect people walking past glass partitions during an evacuation without full insulation requirements.
Choose Class EI if the glass is installed along primary evacuation routes, fire walls separating tenant zones, or areas where occupants may be trapped or slowed down (e.g., healthcare facilities).
Selecting the correct fire glass classification is vital for building compliance and life safety. At [Your Brand Name], we specialize in testing, manufacturing, and supplying certified E, EW, and EI class fire-rated glass solutions tailored to your project’s architectonic vision.
[Contact Our Technical Team Today] to request test certificates, samples, or a custom quote.
