Building components and structures can be classified according to their resistance to fire. The class or combinations of classes are usually followed by a number that indicates the time period for which the functional requirement applies.
Examples of classification are EI 30 which means that the structure is fire resistant (E) and insulating (I) for 30 minutes.
| Class | Explanation | Description |
|---|---|---|
| R | Carrying capacity | Refers to the building element's ability to withstand fire on one or more sides, for a specified time and load without losing its stability. |
| E | Integrity (density) | Is the ability of the building element to withstand fire on one side without the fire spreading to the other side of the element through leakage of flames or hot gases. |
| I | Insulation | Is the building element's ability to fire on one side maintain the temperature on the other side below a certain level. |
| W | Radiation | Is the ability of a building element to ensure that in a fire on one side the heat radiation does not exceed a certain level on the other side. |
| M | Mechanical resistance | Is the ability of a building element to withstand a mechanical shock. |
| C | Self closing | Applies to doors and sheep's ability to close automatically. |
| S | Smoke density | Refers to the ability of a building element to reduce or eliminate leakage from one side to the other of gas and smoke. |
| K | Fire protection (flame retardant cover) | Refers to the ability of a cladding to protect the underlying material against, ignition, charcoal, etc. for a specified period of time. |
| Class | Description |
|---|---|
| F | Products that are not classified in any of the other classes. |
| E | Products that can withstand a small flame attack without significant flame spread for a short time. |
| D | Products that meet Class E and can withstand a small flame attack without significant flame spread for a long time. Can also undergo a thermal attack with a single burning object with sufficient delay and limited heat output. |
| C | Products that meet class D but with stricter requirements, and in the case of a thermal attack with a single burning object a limited horizontal flame spread. |
| B | Products that meet Class C but with stricter requirements. |
| A2 | Products that comply with Class B, and the product under conditions of a fully developed fire should not contribute significantly to the fire load or the development of the fire. |
| A1 | The product shall not contribute at any stage of the fire including fully developed fire. |
| Additional ratings for smoke production. | |
| s3 | No restriction on smoke production. |
| s2 | Total smoke production and the increase in smoke production are limited. |
| s1 | More stringent requirements than s2. |
| Additional ratings for burning droplets and particles. | |
| d2 | No limits |
| d1 | No burning drops or particles that last longer than a certain time have occurred. |
| d0 | No burning drops or particles have occurred. |
| Class | Description |
|---|---|
| F | Products that are not classified in any of the other classes. |
| E | Products that can withstand a small flame. |
| D | Products that meet Class E and can withstand a heat flow attack for a certain period. |
| C | Products that meet Class D but with stricter requirements. |
| B | Products that meet Class C but with stricter requirements. |
| A2 | Products that comply with Class B, and the product under conditions of a fully developed fire should not contribute significantly to the fire load or the development of the fire. |
| A1 | The product shall not contribute at any stage of the fire including fully developed fire. |
| Additional ratings for smoke development. | |
| s2 | No restriction on smoke production. |
| s1 | Total smoke production is limited. |