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IS 16568:2019 Part 1 is the Indian Standard (BIS) for fire resistant door and shutter assemblies - general requirements. This standard specifies the requirements for materials, construction, performance, installation, and labeling of fire resistant door and shutter assemblies. It classifies assemblies based on their fire resistance duration (e.g., 60, 120 minutes) and performance criteria like integrity (E), insulation (I), and radiation (W).
Specifies general requirements for the design, construction, and performance of fire resistant door and shutter assemblies.
Quick Reference — Top IS 16568 Part 1:2019 Values
Key fire resistance ratings, test failure criteria, dimensional tolerances, and hardware requirements for fire door assemblies.
✓ Verified 2026-04-27
Reference
Value
Clause
Standard Fire Resistance Ratings— Based on Integrity (E), Insulation (I), and/or Radiation (W) performance.
30, 60, 90, 120, 180, 240 min
Cl. 5.1 (Table 1)
Classification - Integrity Only (Example)— Prevents passage of flame & hot gas for 60 min. No heat barrier.
E 60
Cl. 5.2.1
Classification - Integrity & Insulation (Example)— EI₁ limits frame temp rise; EI₂ does not. Both limit leaf temp rise.
EI₁ 90 / EI₂ 90
Cl. 5.2.2
Classification - Integrity & Radiation (Example)— Maintains integrity and limits radiated heat for 120 minutes.
EW 120
Cl. 5.2.3
Integrity (E) Failure - Sustained Flaming— Sustained flaming on the unexposed face of the assembly.
> 10 seconds
Cl. 3.10.1
Integrity (E) Failure - Gap Gauge (6 mm)— Indicates a significant opening has formed.
Penetrates > 150 mm
Cl. 3.10.1
Integrity (E) Failure - Gap Gauge (25 mm)— Indicates a major structural failure of the assembly.
Penetrates full thickness
Cl. 3.10.1
Integrity (E) Failure - Cotton Pad— Confirms passage of hot gases sufficient to cause ignition.
Ignition or glowing > 5 sec
Cl. 3.10.1
Insulation (I) Failure - Avg. Temp Rise— Average temperature rise over the initial ambient on the door leaf.
> 140 °C
Cl. 3.11.1
Insulation (I) Failure - Max. Temp Rise— Maximum temperature rise at any single point on the door leaf.
> 180 °C
Cl. 3.11.1
Insulation (I₁) Failure - Frame Temp Rise— For EI₁ classification, the frame temperature rise is also limited.
> 180 °C
Cl. 3.11.1
Radiation (W) Failure Limit— Measured at a distance of 1 m from the geometric centre of the specimen.
> 15 kW/m²
Cl. 3.17
Tolerance - Door Leaf Thickness
± 1.0 mm
Cl. 6.2.1 (Table 2)
Tolerance - Door Leaf Size (H/W)
± 2.0 mm
Cl. 6.2.1 (Table 2)
Tolerance - Door Frame Size (H/W)
± 3.0 mm
Cl. 6.2.1 (Table 2)
Tolerance - Squareness (Diagonal Diff.)— For both door leaf and frame.
≤ 3.0 mm
Cl. 6.2.1 (Table 2)
Tolerance - Flatness (Bow/Twist)— Measured along the length of the component.
≤ 2.0 mm per metre
Cl. 6.2.1 (Table 2)
Max Clearance - Leaf to Frame (Top/Jambs)— Nominal gap. Total gap including tolerance should not exceed 4.0 mm.
3.0 mm (+1 mm tol.)
Cl. 6.2.2
Max Clearance - Between Leaves (Double Door)— At the meeting stiles. Total gap should not exceed 5.0 mm.
4.0 mm (+1 mm tol.)
Cl. 6.2.2
Max Clearance - Leaf to Threshold— May be larger if specified and tested with appropriate bottom seals.
10 mm
Cl. 6.2.2
Self-Closing Device Requirement— All hinged or pivoted fire doors must be self-closing (conforming to IS 3564).
Mandatory
Cl. 8.4
⚠ Verify against the latest BIS/IRC publication and project specifications. Amendment Slips may modify values.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! The fire rating applies to the complete assembly (leaf, frame, hardware, seals). Any unapproved substitution of components on site voids the certification.
! Correct installation as per Clause 9 is critical for performance. A certified doorset installed incorrectly will fail in a fire.
! The label (Clause 7) is the primary proof of compliance. It must be permanently fixed and legible, containing manufacturer details, fire rating, and a unique serial number.
Fire resistance and smoke control tests for door and shutter assemblies, openable windows and elements of building hardware - Part 1: Fire resistance test for door and shutter assemblies and openable windows
Defines the primary method for fire resistance testing of door assemblies, forming the basis for the Indian standard.
BS 476-22:1987BSI (UK)
HighCurrent
Fire tests on building materials and structures. Methods for determination of the fire resistance of non-loadbearing elements of construction
An influential older standard providing fire resistance test methods that are conceptually similar to the IS code.
UL 10CUnderwriters Laboratories (US)
MediumCurrent
Positive Pressure Fire Tests of Door Assemblies
Covers fire testing of door assemblies but includes a mandatory hose stream test not found in the IS code.
NFPA 252National Fire Protection Association (US)
MediumCurrent
Standard Methods of Fire Tests of Door Assemblies
A North American standard very similar to UL 10C, specifying fire-endurance and hose stream tests for door assemblies.
Key Differences
≠The most significant difference with North American standards (UL 10C/NFPA 252) is the lack of a mandatory hose stream test in IS 16568. The IS code, like its European counterpart EN 1634-1, does not require the hot door assembly to be subjected to the thermal shock and impact of a high-pressure water stream after the fire exposure.
≠IS 16568 provides its own classification system (e.g., FRD-60 for a 60-minute fire rating). The European system (EN 13501-2) uses test results from EN 1634-1 to provide more granular classifications like E (Integrity), I (Insulation), and W (Radiation), resulting in ratings such as EI 60 or EW 30, which gives more specific performance information.
≠While IS 16568 is a comprehensive document, the European system supplements EN 1634-1 with an extensive suite of Extended Application (EXAP) standards (the EN 15269 series). These provide extremely detailed and prescriptive rules on how a tested door design can be modified (e.g., changing size, hardware, vision panels) without requiring a new fire test. The rules for variation in IS 16568 are less extensive.
≠The European standards framework distinctly separates fire resistance testing (EN 1634-1) from smoke leakage testing (EN 1634-3), leading to separate 'S' classifications (Sa, Sm). IS 16568 primarily focuses on fire resistance (integrity and insulation) and does not integrate a specific, mandatory smoke leakage test method and classification within the standard itself.
Key Similarities
≈Both IS 16568 and its international counterparts (like EN 1634-1) are based on the same standard time-temperature curve defined in ISO 834-1. This ensures that the heating conditions inside the test furnace are consistent and comparable across different laboratories and standards worldwide.
≈The core failure criteria for Integrity are conceptually identical. Both IS 16568 and EN 1634-1 define integrity failure by the formation of openings that allow passage of specific gap gauges or by the presence of sustained flaming (over 10 seconds) on the unexposed face.
≈The criteria for Insulation failure are aligned. Both standards consider insulation to be lost when the average temperature rise on the unexposed face exceeds 140°C above ambient, or the maximum temperature at any single point exceeds 180°C above ambient.
≈IS 16568 specifies a positive pressure regime inside the furnace, with the neutral pressure plane set at 500 mm above the sill. This aligns with modern international standards like EN 1634-1 and UL 10C, which have moved away from older, less realistic neutral pressure tests to better simulate conditions in a real fire.
Parameter Comparison
Parameter
IS Value
International
Source
Time-Temperature Curve Source
As per ISO 834-1
As per ISO 834-1
BS EN 1634-1
Integrity Failure (Sustained Flaming)
More than 10 seconds on unexposed face
More than 10 seconds on unexposed face
BS EN 1634-1
Insulation Failure (Average Temp. Rise)
Exceeds 140 °C above ambient
Exceeds 140 °C above initial average temperature
BS EN 1634-1
Insulation Failure (Maximum Temp. Rise)
Exceeds 180 °C above ambient
Exceeds 180 °C above initial average temperature
BS EN 1634-1
Furnace Neutral Pressure Axis
500 mm above the sill
500 mm above the sill (for doors)
BS EN 1634-1
Hose Stream Test
Not required
Required for certain ratings and jurisdictions
UL 10C
Classification System
Duration-based (e.g., FRD-30, FRD-60, FRD-120)
Performance-based (e.g., E 30, EI 60, EW 20)
BS EN 13501-2
Thermocouple on Unexposed Door Leaf
5 thermocouples (1 at center, 4 at quarter sections of each leaf)
5 thermocouples (1 at center, 4 at center of each quarter section)
BS EN 1634-1
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Fire Resistance Classes (minutes)30, 60, 90, 120, 180, 240
Performance Criteria NotationE (Integrity), I (Insulation), W (Radiation)
Maximum permitted gap between leaf and frame (un-latched)3 mm
Maximum permitted gap at threshold20 mm (may be reduced based on smoke control requirements)
Door leaf thickness tolerance± 2 mm
Door leaf width/height tolerance± 3 mm
Tables & Referenced Sections
Key Tables
Table 1 - Classification of Fire Resistance
Table 2 - Performance Requirements for Fire Resistance
Table 3 - General Tolerances on Dimensions of Doorset Components
Key Clauses
Clause 4 - Materials
Clause 5 - Construction Requirements
Clause 6 - Performance Requirements
Clause 7 - Marking and Labelling
Clause 9 - Installation
Annex A - Typical Arrangements of Fire Resistant Doorsets
It means the door assembly prevents the passage of flames (Integrity 'E') and limits the temperature rise on the non-fire side (Insulation 'I') for a minimum of 120 minutes when tested.
Can I install a glass vision panel in a fire door?+
Yes, provided the glass and its glazing system have been tested and certified as part of that specific fire door assembly (Clause 4.5).
What is the difference between this code and IS 3614?+
IS 16568 is a modern, comprehensive standard harmonized with international norms (like EN standards). It specifies performance criteria (E, I, W) for the entire assembly, whereas IS 3614 was an older, more prescriptive standard.
Is a door closer mandatory on a fire door?+
Yes, any hinged or pivoted fire door must be fitted with a self-closing device to ensure it is closed during a fire (Clause 4.6.4).