27 C.F.R. § 555.220

Current through October 31, 2024
Section 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.)
OverNot overAmmonium nitrateBlasting agent
10031112
10030041412
30060051812
6001,00062212
1,0001,60072512
1,6002,00082912
2,0003,00093215
3,0004,000103615
4,0006,000114015
6,0008,000124320
8,00010,000134720
10,00012,000145020
12,00016,000155425
16,00020,000165825
20,00025,000186525
25,00030,000196830
30,00035,000207230
35,00040,000217630
40,00045,000227935
45,00050,000238335
50,00055,000248635
55,00060,000259035
60,00070,000269440
70,00080,0002810140
80,00090,0003010840
90,000100,0003211540
100,000120,0003412250
120,000140,0003713350
140,000160,0004014450
160,000180,0004415850
180,000200,0004817350
200,000220,0005218760
220,000250,0005620260
250,000275,0006021660
275,000300,0006423060

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 all ammonium nitrate with respect to its separation from stores of high explosives and blasting agents. Ammonium nitrate explosive mixtures that are high explosives pursuant to § 555.202(a) or are defined as a blasting agent pursuant to § 555.11 are subject to the table of distances for storage of explosive materials in § 555.218 and to the table of separation distances of ammonium nitrate and blasting agents from explosives or blasting agents in this section.
(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.

27 C.F.R. §555.220

84 FR 12097 , 5/31/2019