Fire-rated glass — also called fireproof glass, fire-resistant glass or fire retardant glass — is one of the most misunderstood products in building glazing. Many specifiers assume all “safety glass” can stop a fire. It cannot. Tempered glass is strong; fire-rated glass is certified to contain fire for a defined period of time — usually 30, 60, 90 or 120 minutes.
If you are specifying fire doors, stairwell enclosures, corridor glazing or high-rise partitions, this guide explains what fire-rated glass is, how the ratings work, and how to choose the right type.
What Is Fire-Rated Glass?
Fire-rated glass is a glazing product that has been tested to a recognized fire standard (EN 1363-1 / EN 13501-2 in Europe, GB 15763.1 in China, BS 476 in the UK) and shown to prevent the passage of fire, smoke and — in higher classes — radiant heat for a set time.
It is not a single material. Fire-rated glass can be:
- Borosilicate glass — a monolithic, low-expansion glass that withstands thermal shock
- Ceramic fire glass — monolithic ceramic that resists extreme temperatures
- Laminated intumescent glass — two or more panes bonded with interlayers that foam up and insulate when heated (the most common type for doors and partitions)
- Wired / mesh glass — traditional glass with embedded wire mesh that holds fragments
How Fire Ratings Work: 30, 60, 90, 120 Minutes
A fire rating is expressed as a class + time, for example EI 60 or EW 30. The class describes what the glass stops; the time describes how long it does it under standard test conditions.
The three classes: E, EW, EI
| Class | Meaning | Stops | Typical application |
|---|---|---|---|
| E | Integrity | Flames and hot smoke pass-through | Escape routes, vision panels |
| EW | Integrity + radiation control | Flames, smoke, most radiant heat | Corridors, lobbies |
| EI | Integrity + insulation | Flames, smoke, radiant heat — cool non-fire side | Fire doors, stairwells, partitions |
E (Integrity): the glass stays in place and stops flames and hot smoke passing through. Radiant heat can still pass, which is acceptable in some escape routes.
EW (Integrity + radiation): the glass also limits radiant heat so people can pass nearby without severe heat exposure.
EI (Integrity + insulation): the glass also keeps the non-fire side cool (typically below 140 °C average on the unexposed face). EI is what you need for stairwells and escape corridors where people move right next to the glass during a fire.
What the times mean
| Rating | How long the system resists fire | Typical build |
|---|---|---|
| 30 minutes | Short evacuation window | Single-pane borosilicate (E), laminated intumescent (EI) |
| 60 minutes | Standard commercial requirement | Laminated intumescent, 20–30 mm |
| 90 minutes | High-rise stairwells | Multi-layer laminated, 30–40 mm |
| 120 minutes | Severe fire barriers | Multi-layer laminated / ceramic systems, 40–50 mm+ |
⚠️ Critical: A fire rating is certified for the complete glazing system — glass + frame + seals + installation. Putting fire-rated glass in a non-rated frame does not make the assembly fire-rated. Always confirm frame compatibility.
Fire-Rated Glass vs Tempered Glass: The Key Difference
This is the question we hear most from buyers searching for “fire rated toughened glass” and “fireproof glass panels.”
- Tempered (toughened) glass is mechanically strong: it is 4–5× stronger than annealed glass and breaks into small blunt granules. But standard tempered glass is not fire-rated — it will crack and fall out under fire conditions.
- Fire-rated glass is fire-tested: it holds its integrity (and possibly insulation) for a rated time.
They are not competitors — they are combined. High-quality fire doors commonly use fire-rated toughened glass: tempered glass that is also tested and certified to a fire rating, offering both impact safety and fire containment. When you specify fire-rated glazing, always state the fire rating explicitly rather than assuming tempering is enough. See our fire rated glass products page for available ratings and specifications.
How to Choose Fire-Rated Glass for Your Project
1. Start with the local fire code. Your project’s fire safety specification determines the required class (E / EW / EI) and time (30 / 60 / 90 / 120). Do not design backwards from the glass.
2. Match the rating to the application.
| Application | Typical requirement |
|---|---|
| Internal vision panels, fire windows | E or EW 30–60 |
| Fire doors | EI 30–60 (often EI 60 in commercial buildings) |
| Corridor and lobby glazing | EW / EI 60 |
| Stairwell enclosures | EI 60–120 |
| High-rise fire barriers | EI 90–120 |
3. Confirm sizes early. Laminated intumescent fire glass cannot be cut on site — cutting damages the edge seal of the intumescent layers. Send exact finished dimensions from your frame supplier.
4. Consider exterior use. Intumescent interlayers must be protected from UV and extreme temperatures outdoors. For facades, fire glass is usually built into an insulated glass unit with a protective outer pane.
5. Verify certification. Ask for the test certificates and the standard they comply with (EN 13501-2 / GB 15763.1). A “fireproof glass” claim without a certificate is just marketing.
Fire-Rated Glass Applications at a Glance
- Fire-rated doors and partitions
- Staircase enclosures and lift lobby glazing
- Emergency escape routes and corridor glazing
- High-rise building fire barriers
- Fire-rated vision panels in industrial buildings
FAQ
Q: What is fire rated glass made of?
A: The main types are borosilicate glass, ceramic fire glass, laminated intumescent glass (2+ panes with fire-foaming interlayers) and wired glass. Laminated intumescent is the most common for EI-class doors and partitions.
Q: What does EI 60 mean?
A: EI 60 means the glazing system maintains both integrity (blocks fire and smoke) and insulation (keeps the non-fire side cool) for 60 minutes under standard fire testing.
Q: Is tempered glass fire rated?
A: Not automatically. Standard tempered glass is strong but not fire-rated. Fire-rated toughened glass is tempered glass that has also been tested and certified to a fire rating — specify the rating explicitly if you need it.
Q: Can fire rated glass be cut to size?
A: Laminated fire-rated glass must be ordered in finished sizes. Single-pane borosilicate and ceramic types can be processed, but confirm with the manufacturer before cutting.
Q: How thick is fire rated glass?
A: Typically from 6–8 mm (single-pane E-class) to 40–50 mm+ (EI 120 multi-layer systems), depending on the rating and type.
Q: Do you supply fire rated glass with certificates?
A: Yes — Dongguan Safety Glass supplies fire-rated glass to 30/60/90/120 minutes with CE (EN 13501) and GB 15763 certification, with certificates included in every shipment.
Need Fire-Rated Glass for Your Project?
Dongguan Safety Glass Products Co., Ltd. is a factory-direct fireproof glass manufacturer in Dongguan, China, exporting to 50+ countries with CE and ISO 9001 certification. Send your fire safety specification and drawings for a same-week quotation:
- Email: nicole@dgsafetyglass.com
- WhatsApp: +86-15917659254
- Website: www.dgsafetyglass.com
Fire ratings available: E / EW / EI — 30, 60, 90, 120 minutes · Thickness 15–50 mm+ · Export-grade wooden crate packing