Separation distances
Required separation distances, hazard class 1.1
The separation distance between the storage facility and surrounding protected sites must be sufficient. The required distance is determined according to the hazard class of the explosives and the type of the protected site.
Requirements for the separation distances of permanent and temporary storage facilities are identical.
The required separation distance for hazard class 1.1 explosives is calculated by the formula s = k∛m, in which k is the coefficient for the type of protected site and m is the net explosive quantity to be stored in kilograms. The distance is given in metres.
The value for the coefficient k can be found in the table below.
Values for the coefficient k used in calculating the separation distances for aboveground storages
| Category of the protected site | Protected site |
| A | hospitals, prisons, care homes, nursing homes, day cares or other similar institutions that house people who need assistance with evacuating the premises |
| B | schools, residential areas of at least 10 households, sports facilities, meeting places or other spaces that regularly house people, public buildings or manufacturing facilities of hazardous chemicals operated by a third party |
| C | a single residential building or other industrial building |
| D | public roads, harbour areas, airport runways or pressure regulating stations of a natural gas transmission pipeline |
| E | public roads with little traffic |
Values for coefficient k
| Protected site | Value of k according to the hazard class and projection hazard | |||
| 1.1 and 1.5 | 1.2 and 1.6 | |||
| No projection hazard | Projection hazard | No projection hazard | Projection hazard | |
| A | 60 | 60 | 58 | 76 |
| B | 30 | 30 | 58 | 76 |
| C | 22 | 22 | 58 | 76 |
| D | 15 | 15 | 39 | 51 |
| E | 10 | 10 | 39 | 51 |
By using the modified formula m = (s/k)3, you can calculate the maximum allowed amount of explosive material if you know the distance between the storage facility and the protected site and use the value for k provided for that protected site.
However, the distance between the storage facility and all surrounding protected sites must be at least the minimum distance provided. See the table ‘Storage facility separation distances for surrounding protected sites, other than retail’ below.
The distances are calculated from the storage facility wall that is nearest to the protected site. If the facility has several storage buildings, the distance must be calculated for each building separately. The separation distance between the storage buildings must also be sufficient.
The separation distance between the storage buildings must be at least the distance that the formula s = k∛m produces. In other cases, the separation distance to surrounding sites is calculated by using the total amount of explosive material in the storage facility. In the formula, coefficient k is determined according to the level of protection of the storage building and m is the net explosive quantity to be stored in kilograms. The values for coefficient k can be found in the table ‘Values for coefficient k’. For storage facilities intended for civil explosives and detonators, the separation distance in calculated by using the values for the detonators only. The accidental detonation of the detonators must not reach the civil explosives. The detonation of the civil explosives would be so large in scale that it makes no difference if the detonators accidentally detonate as well.
The table ‘Calculated separation distances’ includes calculated distances for a variety of values of k.
Example: Permanent storage for explosives for civil use, calculating separation distances
The planned amount of explosive material to be stored is 16,000 kg. The distance from the planned location of the storage building to the nearest residential building is 450 metres and 275 metres to the nearest national road.
The explosives belong to hazard class 1.1 but do not have a projection hazard.
According to table A, the single residential building falls under the protected site class C, which means the value for coefficient k is 22. The national road falls under class D, which means the value for coefficient k is 15. The minimum separation distances to the residential building and the national road are calculated by the formula s = k∛m.
s = 22 ∛16000 s = 555 metres from the residential building. This means the planned distance is not sufficient.
s = 15 ∛16000 s = 378 metres from the national road. This means the distance from the road is not sufficient either.
The formula m = (s/k)3 can be used to calculate the maximum allowed amount of explosive material that can be stored in one storage building.
m = (450/22)3 = 8 555 kg (residential building) and m = (275/15)3 = 6 160 kg (national road)
In conclusion, one storage building can hold only 6,160 kilograms of explosives.
It is possible to build two separate storage buildings. This solution is of course dependent on the where the residential building, the national road and the storage buildings are located in relation to each other. According to the formula s = 3 ∛6000, the separation distance between two storage buildings holding 6000 kg of explosives must be at least 55 metres. If each storage building has a protective barrier, the distance between them must be at least s = 1,5 ∛6000 = 27,5 metres.
Required separation distances, hazard class 1.3
The required minimum separation distance for hazard class 1.3 explosives is 30% of the minimum distance required for hazard class 1.1 explosives. However, the minimum distance to all surrounding sites is 100 metres.
Required separation distances, hazard class 1.4
No formula exists for calculating separation distances for hazard class 1.4 explosives.
However, for explosives with a projection hazard and storages holding more than 1,000 kg of explosives, the minimum distance is 100 metres from all protected sites. If the amount of explosive material stored is 100–1,000 kg, the distance must be at least 50 metres. For storages holding less than 100 kg of explosives and for hazard class 1.4S explosives, the required minimum separation distance is 25 metres.
Storage facility separation distances for surrounding protected sites, other than retail
| Hazard class and amount (in kg) | Site and minimum distance | ||
| Area with a local detailed plan, single residential building or other building, industrial facility or area with people | Public road with more than little traffic, railroad, shipping lane, pressure regulating station of a natural gas transmission pipeline or other site important to the society | ||
| Hazard classes 1.1 and 1.5 |
projection hazard | 300 m | 200 m |
| no projection hazard | 100 m | 100 m | |
| Hazard classes 1.2 and 1.6 |
projection hazard | 300 m | 200 m |
| no projection hazard | 100 m | 100 m | |
| Hazard class 1.3 | amount 100–1,000 kg | 50 m | 50 m |
| projection hazard or amount more than 1,000 kg | 100 m | 100 m | |
| Hazard class 1.4 |
hazard class 1.4S explosives or a less than 100 kg storage for other class 1.4 explosives | 25 m | 25 m |
