Background
The BS EN Test standards1 were published in 2025 and present a comprehensive method of assessing the performance of such products against blast loading from external explosive threats. The standards provide several different blast Loading Categories representing likely threats from Vehicle Borne Improvised Explosive Devices (VBIED) and Person Borne Improvised Explosive Devices (PBIED) and also a method of assessing the resulting damage and the associated hazards for people both inside and outside a building.
Glazed curtain walling may incorporate doors and non-glazed panels. Similarly, non-loadbearing walls may contain windows and doors. The blast performance of such doors, non-glazed panels and walls will need to be assessed. However, the BS EN standards does not provide a method for assessing the damage to and hazard from these components due to blast loads.
Aim
The aim of this document is to supplement the BS EN standards by providing a method for testing external doors, non-glazed panels and non-loadbearing walls under blast loading from external IEDs and assessing the damage and hazard to people.
Introduction
This supplement provides guidance on:
- Test Requirements
- Test Specimens
- Hazard Assessment
Other aspects of the test should follow the procedures in the BS EN Standards.
Test Requirements
The Test Client shall define:
- The Loading Category that is required
- The maximum Hazard Rating that is acceptable
In addition, there is a need to specify the condition of a door set before and after the test to reflect its use when installed. The Test Client shall specify:
- Before the test, whether the door is to be locked or unlocked and latched or free to open.
- After the test, whether the door should remain secure, be still operable, be openable with limited tools or may be jammed shut.
This supplement is applicable for inward or outward swinging single-leaf or double-leaf doors. For sliding or rotating doors the interpretation of the hazard levels will need to be agreed between the Test Client and the Test Facility.
Doors and walls should be tested against the same blast loads as the glazing in the same building façade. For both large charge sizes (VBIED threats) and small charges (PBIED threats) the blast Loading Categories in the BS EN standards should be used.
Test Specimens
Doors
Door test specimens must be mounted in the reaction structure together with a sufficient expanse of wall to ensure that the behaviour of the door set fully reflects its behaviour when installed in a building façade.
The door frame shall be fixed into the wall using the number, size and type of fixings specified by the manufacturer or designer. The complete door set shall include all hinges, locks and fittings. At least 75% of these fixings shall remain after the test.
For curtain walling systems doors, together with their frames, must be tested mounted in the system in which they are to be installed.
For other wall types the door sets should be mounted directly into the wall.
In cases where the door set is mounted in an H-frame, comprising two mullions and a header beam, the test specimen shall comprise the door set mounted in the H-frame together with sufficient wall on either side to ensure the connections between the wall and H-frame can be assessed.
It is recommended that high-speed video cameras are used so that any door movement during the test can be examined.
For frameless glazed doors, furniture such as top / bottom bars, patches or hinges should be assessed separately where they become detached from the door pane. In cases where they remain fully attached to the door pane they may be considered as part of the door leaf.
Damage to any vision panels in opaque doors should be assessed in accordance with the BS EN standard for windows and curtain walling.
Non-glazed infill panels and spandrel panels
The hazard rating system for non-glazed panels and walls shall be used for testing components incorporated within a curtain wall or installed adjacent to a curtain wall such as spandrel panels and infill panels.
Such panels shall be tested mounted adjacent to or mounted in the curtain walling system with which they will be installed. The test configuration must ensure that the way the component is loaded and supported is fully representative of a real installation.
Walls
Masonry or composite non-loadbearing walls may be tested without openings for windows or doors. However, where walls are to contain windows and/or doors, they must also be tested with them installed.
Wall test specimens shall be mounted in a reaction structure so that they represent an installation in a building. The header details and vertical joints are particularly important to ensure any vertical or horizontal arching effects are correctly reproduced.
Precast cladding panels should be designed as simply supported components to resist the appropriate blast loading with the structural connections being designed to successfully transfer the full resultant load to the structure. Although such panels may have been designed using a validated design method (such as that described in UFC 3-340-0222 ), the loads on the connections to the building structure are likely to be very large and it is recommended that their performance should be verified by tests.
Hazard Assessment
The hazard assessment considers the hazard levels for people inside and outside the building. These are summarised in Figure 1.
The hazard assessment criteria for external doors are shown in Table 1. Internal Hazard and Table 2. External Hazard.
Similarly, the hazard assessment criteria for non-glazed panels and external walls are shown in Table 3. Internal Hazard and Table 4. External Hazard.
When assessing hazard levels for doors it is important that the client’s requirements for the condition of the door after the test are considered e.g. fire doors must still be openable and security doors should remain secure.
Figure 1: iIlustrative cross-section through a test structure showing internal and external hazard levels.
|
Hazard Rating |
Description |
|---|---|
| A No break |
There is no visible damage to the test specimen. All frame fixings shall remain intact. All locks shall remain operational as specified by the test client. |
| B No Hazard |
The test specimen may undergo plastic deformation, but no tears or visible gaps should be created. No component shall become completely detached. The test specimen shall remain securely in place and present no increased hazard. The door remains in a locked/closed position during the test and can be opened manually afterwards. Individual users may require that the door shall be closable and lockable after the test. All locks shall remain operational as specified by the test client. All frame fixings shall remain intact. |
| C Minimal Hazard |
As No Hazard but with the following relaxation of criteria:
|
| D Very low Hazard |
As Minimal Hazard but with the following relaxation of criteria:
|
| E Low Hazard |
As Very Low Hazard but with the following relaxation of criteria:
|
| F High Hazard |
Catastrophic failure of the test specimen. Fragments of any size are projected behind the test specimen at a height greater than 0.5 m at 3 m Permanent deflection at mid-height of any H-frame supporting the door set exceeds the greater of 10 mm or L/360 mm. |
Table 1: Internal hazard ratings for external doors.
| Hazard Rating | Description |
|---|---|
| X No Hazard |
The door is undamaged and the door frame (including associated components and fixings) shows no visible signs of damage. All furniture and framing system components remain fully attached on the external face. |
| Y Limited Hazard |
The door and door frame may show visible signs of damage. The door may open outwards but remains fully or partially attached to its frame at its hinge points and may be opened. Small component parts of the external door furniture, the door frame or fixings (mass < 25 g) may become detached (i.e. small secondary fragments may be produced) and be projected up to a maximum of 3 m from the face of the specimen. No significant frame components are projected more than 3 m from the original exterior face of the test specimen. |
| Z High Hazard |
The door may become completely detached from its frame and falls outward or the door may jam shut. or Large fragments or component parts of the external door furniture, the door frame or fixings (mass > 25 g) are detached and projected more than 3 m from the face of the specimen. or Significant frame components are projected more than 3 m from the outer face of the test specimen. |
Table 2. External hazard ratings for external doors.
| Hazard Rating | Description |
|---|---|
| A No break |
There is no visible damage to the test specimen. All fixings shall remain intact. |
| B No Hazard |
The test specimen may undergo plastic deformation, but no component shall become completely detached. The test specimen shall remain securely in place and present no increased hazard.
|
| C Minimal Hazard |
As No Hazard but with the following relaxation of criteria:
|
| D Very low Hazard |
As Minimal Hazard but with the following relaxation of criteria:
|
| E Low Hazard |
As Very Low Hazard but with the following relaxation of criteria:
|
| F High Hazard |
Catastrophic failure of the test specimen. This will mean either collapse of the wall or complete or partial detachment from the head or base rail tracks (the wall may or may not fall to the back of the test structure). or Complete detachment of the non-glazed panel. or Fragments hit the witness pack 3 m behind the specimen at a height above 0.5 m. or Walls have a central permanent defection greater than 300 mm. or Less than 75 % of fixings and panel connections to the host structure remain intact. |
Table 3: Internal hazard ratings for non-glazed panels and external walls.
| Hazard Rating | Description |
|---|---|
| X No Hazard |
The test specimen may show visible damage and may undergo plastic deformation but no debris is created or projected outward from the external face of the test specimen. Any externally attached components or fixings (if included) remain fully attached. The test specimen, without addition of any temporary support, must not collapse for a minimum of 1 hour after the test. |
| Y Limited Hazard |
The door and door frame may show visible signs of damage. The door may open outwards but remains fully or partially attached to its frame at its hinge points and may be opened. Small component parts of the external door furniture, the door frame or fixings (mass < 25 g) may become detached (i.e. small secondary fragments may be produced) and be projected up to a maximum of 3 m from the face of the specimen. No significant frame components are projected more than 3 m from the original exterior face of the test specimen. |
| Z High Hazard |
The test specimen suffers complete collapse. or Debris created is projected more than 3 m from the original external face of the test specimen. |
Table 4: External hazard ratings for non-glazed panels and external walls.
Footnotes
1BS EN 13123-2:2025 – Windows, doors, shutters and curtain walling – Explosion resistance – Requirements and classification – Arena test
BS EN 13124-2:2025 – Windows, doors, shutters and curtain walling – Explosion resistance – Test method – Arena test
2UFC 3-340-2 Structures to Resist the Effects of Accidental Explosions