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Table 3 External separation distances

Hazard Type 1 in an unmounded brick-built building – normal distances


Quantity of explosives (kg) 		Separation distance (m)
Footpath, lightly used road, waterway Minor road, railway line* Major road, place of public resort, buildings† Vulnerable building distance
0.1 – 25 47 71 141 141
25 – 50 53 80 160 160
50 – 75 60 90 180 180
75 – 100 67 100 199 199
100 – 150 77 115 230 230
150 – 200 85 128 256 256
200 – 300 98 147 293 293
300 – 400 107 160 320 320
400 – 450 110 166 331 331
450 – 500 113 170 340 340
500 – 600 118 178 355 355
600 – 700 122 184 367 367
700 – 800 126 189 377 377
800 – 900 128 193 385 385
900 – 1 000 131 196 392 392
1 000 – 1 100 133 199 398 398
1 100 – 1 200 134 202 403 403
1 200 – 1 300 136 204 408 408
1 300 – 1 400 137 206 412 412
1 400 – 1 500 138 208 415 415
1 500 – 1 600 139 209 418 418
1 600 – 1 700 140 210 421 421
1 700 – 1 800 141 212 424 431
1 800 – 1 900 142 213 426 444
1 900 – 2 000 143 214 428 458
2 000 – 3 000 147 221 442 570
3 000 – 4 000 150 225 449 656
4 000 – 5 000 151 227 454 724
5 000 – 10 000 165 248 495 950
10 000 – 15 000 183 275 550 1 097
15 000 – 20 000 202 303 606 1 211
20 000 – 25 000 218 327 653 1 306
25 000 – 30 000 232 348 695 1 389

Column 1 gives two figures in each row for the quantity of explosives. For example, 25–50 kg means more than 25 kg and up to and including 50 kg.
There is no distance requirement for a quantity of explosives less than the minimum figure given in the table.
Where the quantity of explosives under consideration is greater than the maximum given in this table, the distance may be calculated using the appropriate formula.

Definition of terms
‘Footpath’ includes a bridleway or other thoroughfare which is not a road, but does not include a footpath used by no more than 20 persons every 24 hours.
‘Lightly used road’ means a road used by more than 20 and fewer than 500 vehicles every 24 hours.
‘Minor road’ means a road used by more than 500 vehicles every 24 hours, other than a major road.
‘Major road’ means a road used by more than 10 000 vehicles every 24 hours.
‘Waterway’ does not include a waterway navigated by no more than 20 persons every 24 hours.

* Use these distances also for any aerodrome, dock, pier, jetty, river wall, sea wall, reservoir.
† Use these distances for any dwelling, retail shop, government and public buildings, church, college, chapel, school, hospital, theatre, cinema or other building where the public are accustomed to assemble, motorway; caravan site for which planning permission for this use has been granted and on which is located an occupied caravan for a total period in excess of 28 days in any one calendar year; factory; building or works used for the storage in bulk of petroleum spirit, gas, or other inflammable substances; buildings or works used for the storage and manufacture of explosives or of articles which contain explosives.

Table 3A External separation distances – reduced distances for low-density buildings

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Updated: 2011-10-21