555.220—Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting agents.
Table: Department of Defense Ammunition and Explosives Standards, Table 5-4.1 Extract; 4145.27 M, March 1969
| Donor weight (pounds) | Minimum separation distance of acceptor from donor when barricaded (ft.) | Minimum thickness of artificial barricades (in.) | ||
|---|---|---|---|---|
| Over | Not over | Ammonium nitrate | Blasting agent | |
| 100 | 3 | 11 | 12 | |
| 100 | 300 | 4 | 14 | 12 |
|
Code of Federal Regulations
174
|
||||
| 300 | 600 | 5 | 18 | 12 |
| 600 | 1,000 | 6 | 22 | 12 |
| 1,000 | 1,600 | 7 | 25 | 12 |
| 1,600 | 2,000 | 8 | 29 | 12 |
| 2,000 | 3,000 | 9 | 32 | 15 |
| 3,000 | 4,000 | 10 | 36 | 15 |
| 4,000 | 6,000 | 11 | 40 | 15 |
| 6,000 | 8,000 | 12 | 43 | 20 |
| 8,000 | 10,000 | 13 | 47 | 20 |
| 10,000 | 12,000 | 14 | 50 | 20 |
| 12,000 | 16,000 | 15 | 54 | 25 |
| 16,000 | 20,000 | 16 | 58 | 25 |
| 20,000 | 25,000 | 18 | 65 | 25 |
| 25,000 | 30,000 | 19 | 68 | 30 |
| 30,000 | 35,000 | 20 | 72 | 30 |
| 35,000 | 40,000 | 21 | 76 | 30 |
| 40,000 | 45,000 | 22 | 79 | 35 |
| 45,000 | 50,000 | 23 | 83 | 35 |
| 50,000 | 55,000 | 24 | 86 | 35 |
| 55,000 | 60,000 | 25 | 90 | 35 |
| 60,000 | 70,000 | 26 | 94 | 40 |
| 70,000 | 80,000 | 28 | 101 | 40 |
| 80,000 | 90,000 | 30 | 108 | 40 |
| 90,000 | 100,000 | 32 | 115 | 40 |
| 100,000 | 120,000 | 34 | 122 | 50 |
| 120,000 | 140,000 | 37 | 133 | 50 |
| 140,000 | 160,000 | 40 | 144 | 50 |
| 160,000 | 180,000 | 44 | 158 | 50 |
| 180,000 | 200,000 | 48 | 173 | 50 |
| 200,000 | 220,000 | 52 | 187 | 60 |
| 220,000 | 250,000 | 56 | 202 | 60 |
| 250,000 | 275,000 | 60 | 216 | 60 |
| 275,000 | 300,000 | 64 | 230 | 60 |
Table: National Fire Protection Association (NFPA) Official Standard No. 492, 1968
Notes of Table of Separation Distances of Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents
(1) This table specifies separation distances to prevent explosion of ammonium nitrate and ammonium nitrate-based blasting agents by propagation from nearby stores of high explosives or blasting agents referred to in the table as the “donor.” Ammonium nitrate, by itself, is not considered to be a donor when applying this table. Ammonium nitrate, ammonium nitrate-fuel oil or combinations thereof are acceptors. If stores of ammonium nitrate are located within the sympathetic detonation distance of explosives or blasting agents, one-half the mass of the ammonium nitrate is to be included in the mass of the donor.
(2) When the ammonium nitrate and/or blasting agent is not barricaded, the distances shown in the table must be multiplied by six. These distances allow for the possibility of high velocity metal fragments from mixers, hoppers, truck bodies, sheet metal structures, metal containers, and the like which may enclose the “donor.” Where explosives storage is in bullet-resistant magazines or where the storage is protected by a bullet-resistant wall, distances and barricade thicknesses in excess of those prescribed in the table in § 555.218 are not required.
(3) These distances apply to ammonium nitrate that passes the insensitivity test prescribed in the definition of ammonium nitrate fertilizer issued by the Fertilizer Institute. 1 Ammonium nitrate failing to pass the test must be stored at separation distances in accordance with the table in § 555.218.
(4) These distances apply to blasting agents which pass the insensitivity test prescribed in regulations of the U.S. Department of Transportation (49 CFR part 173).
(5) Earth or sand dikes, or enclosures filled with the prescribed minimum thickness of earth or sand are acceptable artificial barricades. Natural barricades, such as hills or timber of sufficient density that the surrounding exposures which require protection cannot be seen from the “donor” when the trees are bare of leaves, are also acceptable.
(6) For determining the distances to be maintained from inhabited buildings, passenger railways, and public highways, use the table in § 555.218.