A fire door classification is a compact code for a large amount of tested performance. Read it correctly and it tells you exactly what the doorset was verified to do. Read it loosely and you can specify the wrong door with complete confidence.
EN 13501-2 classifies the fire resistance of a doorset using a letter sequence followed by a time in minutes. E is integrity, I is insulation, EI₂ is the standard insulation measurement for doors, EW is integrity plus limited radiation, and Sa or S200 describe smoke leakage. A classification such as EI₂ 60 Sa is a full statement of what the doorset resists and for how long.
EN 13501-2 is the European standard that classifies the fire resistance of construction products, including doorsets, using results from EN 1634-1 fire tests. The classification is built from letters that describe what was measured and a number that states the duration in minutes. Once you know what each letter carries, a classification stops being jargon and becomes a precise specification instruction.
The letters — what was tested
Each letter in a classification represents a distinct performance criterion that the doorset either met or did not:
- E — integrity. The door resists the passage of flame and hot gases from the fire side to the unexposed side. Every fire classification includes E; it is the baseline.
- I — insulation. The door also limits the temperature rise on the unexposed face, so it does not become a heat source or radiate enough to block an escape route. This is the criterion that separates a full fire door from one that only holds back flame.
- W — radiation. An intermediate measure: the door limits radiated heat through the assembly without meeting the full insulation limit. EW sits between E and EI.
So an E 60 door holds back flame for 60 minutes but makes no promise about heat transfer. An EI 60 door does both. Specifying E where the fire strategy needs EI is the single most common classification error, and it is invisible until the strategy is tested against the schedule.
E holds back flame. EI holds back flame and heat. Specifying E where the strategy needs EI is the most common classification error — and the hardest to spot on a door schedule.
The subscript — EI₁ vs EI₂
The subscript on an insulation classification defines where the temperature rise is measured near the edge of the door leaf. EI₁ applies a stricter temperature limit measured closer to the frame; EI₂ applies the limit at a measurement point that reflects a realistic position on the leaf and frame. Both are full insulation classifications — EI₂ is not a lesser rating, it is a different, widely accepted measurement basis for doorsets.
All DFM DS fire-rated doorsets are classified EI₂, across the range from EI₂ 30 to EI₂ 120. EI₂ 120 is held as a standard catalogue item rather than a bespoke build, which means the highest insulation duration in the range carries no lead-time premium.
The number — duration in minutes
The figure after the letters is the classification period in minutes: 30, 60, 90 or 120. It states how long the doorset maintained the classified criteria under test, not a guaranteed real-world survival time. The fire strategy sets the required period for each opening; the schedule must then call the matching classification, and the Declaration of Performance must carry it.
Smoke — Sa and S200
Smoke control is classified separately from fire resistance, under EN 13501-2 using EN 1634-3 test evidence. Two designations matter for doorsets:
- Sa — ambient smoke leakage. Leakage measured at ambient temperature, for controlling cold smoke spread.
- S200 — medium-temperature smoke leakage. Leakage measured at 200°C, a more demanding condition for warm smoke.
Where a fire strategy calls for smoke control, the smoke classification must be stated alongside the fire classification. It is worth knowing that a component approval for a smoke seal is not the same as a tested smoke classification for the assembled doorset — the classification belongs to the doorset as tested, not to a gasket in isolation.
The DFM DS classification table
The full EN 13501-2 classifications for the DS range, as stated in ETA-22/0324:
| Product | Fire classification | Smoke classification |
|---|---|---|
| DS 30-1 / 30-2 | EI₂ 30 | Sa4 / S200 |
| DS 60-1 / 60-2 | EI₂ 60 | Sa4 / S200 |
| DS 90-1 | EI₂ 90 | Sa / S200 |
| DS 120-1S / 120-2S | EI₂ 120 | Sa4 / S200 |
Note the DS 90 smoke classification is Sa, while DS 30, 60 and 120 are classified Sa4. All DS fire-rated doorsets are CE marked for internal applications under ETA-22/0324, issued by OiB Vienna (Notified Body 1322), with evidence drawn from six independent European test institutes.
Reading a full classification
Put the parts together and a classification reads as a complete instruction. EI₂ 60 Sa4 means: integrity and insulation, measured on the EI₂ basis, maintained for 60 minutes, with ambient smoke leakage controlled to Sa4. A door schedule entry that states only “FD60” carries none of that detail. Writing the EN classification in full is what makes the specification unambiguous at Gateway and at handover.
Frequently Asked Questions
What does EI₂ mean on a fire door?
EI₂ is a full insulation classification under EN 13501-2. E confirms integrity (resistance to flame and hot gas) and I confirms insulation (limiting temperature rise on the unexposed face). The subscript 2 defines where the temperature rise is measured near the leaf edge. EI₂ is a widely accepted measurement basis for doorsets, not a lesser rating.
What is the difference between E and EI fire ratings?
An E classification confirms integrity only — the door resists flame and hot gases. An EI classification confirms integrity and insulation, so the door also limits heat transfer to the unexposed side. Where a fire strategy requires insulation, EI is the correct specification; E alone is not a substitute.
What do Sa and S200 mean?
They are smoke leakage classifications. Sa is ambient-temperature smoke leakage, for controlling cold smoke. S200 is leakage measured at 200°C, a more demanding warm-smoke condition. Where smoke control is required, the smoke classification is stated alongside the fire classification, e.g. EI₂ 60 Sa.
Is EI₂ 60 the same as FD60?
No. FD60 references a BS 476-22 test result and does not, on its own, confirm insulation performance. EI₂ 60 is an EN 13501-2 classification from an EN 1634-1 test confirming both integrity and insulation for 60 minutes. Specify using the EN classification.
What classifications does the DFM DS range hold?
The DS range is classified EI₂ from 30 to 120 minutes. DS 30, 60 and 120 carry Sa4 / S200 smoke classification; DS 90 carries Sa / S200. All are CE marked for internal applications under ETA-22/0324, issued by OiB Vienna (Notified Body 1322).
