Anyone who looks into fire safety regulations quickly runs into a wall of abbreviations and standards. In this article, we outline the key terms.
We start with who makes and checks the rules, and then go through the terms you come across in advice, quotations and inspection reports: compartments, escape routes, WBDBO, fire resistance classes and the standards behind them.
Who decides what?
- The Besluit bouwwerken leefomgeving (Bbl) contains the statutory requirements for building and for fire-safe use. For the determination methods, it refers to NEN standards.
- Usually the municipality is the competent authority: it grants permits, receives notifications and enforces. The safety region or fire service advises and may, depending on local arrangements and powers, be involved in supervision.
- Certification bodies such as Kiwa assess companies and products. A certified company works to defined requirements and is audited periodically.
- Insurers sometimes set additional requirements, for example for sprinklers, compartmentation or demonstrable maintenance.
Active versus passive
Active fire safety intervenes during a fire: think of smoke detectors, sprinklers and extinguishing equipment. Passive fire safety is built into the structure itself and slows the spread of fire and smoke.
A wall, floor or seal needs no detection or power to do its job. Even so, passive provisions are not entirely independent of installations and use. A fire door held open on a free-swing closer or hold-open magnet must be released in a fire, often by the fire alarm system. A fire damper must close, and a door wedged open protects nothing. Passive and active provisions together form the fire safety concept.
Compartments and escape routes
The Bbl divides a building into areas, each with its own level of protection. These are the terms you will come across most often:
| Term | What it means |
|---|---|
| Fire compartment | The area within which a fire must be contained, bounded by fire-resistant walls and floors. |
| Fire sub-compartment | A smaller area within a fire compartment, such as a dwelling or hotel room, that further limits the spread of fire. |
| Protected fire sub-compartment | A fire sub-compartment with additional requirements, among others where people stay who cannot escape on their own, as in certain residential functions for care and healthcare with a bed area. |
| Protected escape route | An escape route outside the fire sub-compartments, with requirements for resistance to fire and smoke. |
| Extra-protected escape route | A protected escape route subject to stricter requirements, for example a stairwell. |
WBDBO: the core of compartmentalization
WBDBO stands for resistance to fire penetration and fire spread: the time it takes before fire spreads from one compartment to another. Walls, floors, doors, seals, and penetrations must together achieve this resistance.
In addition to the WBDBO, the Bbl sets requirements for resistance to smoke passage, determined in accordance with NEN 6075. The term ‘smoke compartment’ comes from older regulations; the Bbl no longer uses it. In a fire, smoke is often life-threatening sooner than the flames, and a separation that stops flames but lets smoke through does not adequately protect people escaping.
How the WBDBO is determined and where things go wrong is explained in WBDBO explained.
Reading a fire resistance class
Fire resistance is determined according to NEN 6069, which follows the European standards for testing and classification. A classification consists of letters and a time in minutes:
| Letter | Meaning |
|---|---|
| R | Load-bearing capacity: the structure keeps carrying its load. |
| E | Integrity: no flames or hot gases pass through. |
| I | Thermal insulation: the unexposed side does not get too hot. |
| W | Limitation of heat radiation, for example with fire-resistant glass. |
| S | Smoke leakage: Sa at room temperature, S200 also at 200 °C. |
| C | Self-closing: the door closes by itself, with a number for the number of tested closing cycles. |
So REI 90 means that in the test a floor keeps its load-bearing capacity, integrity and insulation for 90 minutes. EI 60 means that in the test a wall or seal provides integrity and insulation for 60 minutes. A door classified EI2 30-C5 Sa is fire-resistant for 30 minutes, self-closing and smoke-resistant at room temperature.
The difference between EI 30 and EI 60 in practice is explained in EI 30 or EI 60?
Key standards at a glance
| Standard | What it's about |
|---|---|
| NEN 6068 | Determination method for the WBDBO between spaces |
| NEN 6069 | Testing and classification of construction products for fire resistance |
| NEN 6075 | Determination method for resistance to smoke penetration between rooms |
| NEN 6090 | Determination of the fire load of a room |
| NEN-EN 13501-1 | Reaction-to-fire class: how a building product itself contributes to a fire |
| NEN-EN 13501-2 | European classification of fire resistance with the letters R, E, I, S and C |
| NEN-EN 1366 | Series of standards for fire resistance of building services provisions (seals, dampers) |
| NEN-EN 1634 | Fire resistance of doors, hatches, and openable windows |
What does this mean for you in practice?
- Every penetration, door or wall that forms part of a compartment separation must demonstrably deliver the required performance
- A classification applies to the whole system: product and installation, within the field of application
- A modification to one component can affect the fire resistance of the whole
- A product is only demonstrably fire-resistant within its substantiated field of application: the tested situation plus the permitted extensions, such as wall type, pipe type and maximum opening
- Record what has been applied where, so that you can demonstrate it in one go during an inspection
Not sure whether your building still complies? The free online quickscan gives a first indication within a few minutes; an on-site inventory shows what is really needed.
Frequently asked questions
Fire resistance is about how long a building element resists fire, expressed in minutes, such as EI 60. The reaction-to-fire class is about how a material itself contributes to a fire, from A1 (non-combustible) to F.
For new construction, the starting point is 60 minutes. The Bbl has exceptions, for example 30 minutes between a residential function and an enclosed space through which an extra-protected escape route runs, and a reduction for a low permanent fire load. For existing buildings, at least 20 minutes generally applies, and for renovations the lawfully obtained level.
The municipality is the competent authority and can inspect and enforce, often advised by the fire department. Insurers and certification bodies also take a look. The responsibility for compliance lies with the owner and the user of the building.
Want to know more about fire-resistant seals?
Sealing penetrations against fire with collars, wrap strips, sealant, mortar or other systems with a substantiated application, so that the WBDBO of your fire separation stays intact.
More about fire-resistant seals
