(a) The classification code for an explosive, which is assigned by the Associate Administrator in accordance with this subpart, consists of the division number followed by the compatibility group letter. Compatibility group letters are used to specify the controls for the transportation, and storage related thereto, of explosives and to prevent an increase in hazard that might result if certain types of explosives were stored or transported together. Transportation compatibility requirements for carriers are prescribed in Secs. 174.81, 175.78. 176.83 and 177.848 of this subchapter for transportation by rail, air, vessel, and public highway, respectively, and storage incidental thereto.
(b) Compatibility groups and classification codes for the various types of explosives are set forth in the following tables. Table 1 sets forth compatibility groups and classification codes for substances and articles described in the first column of table 1. Table 2 shows the number of classification codes that are possible within each explosive division. Altogether, there are 35 possible classification codes for explosives.
Table 1--Classification Codes------------------------------------------------------------------------
Description of substances or Compatibility Classification
article to be classified group code------------------------------------------------------------------------Primary explosive substance....... A 1.1AArticle containing a primary B 1.1B
explosive substance and not 1.2B
containing two or more effective 1.4B
protective features. Some
articles, such as detonators for
blasting, detonator assemblies
for blasting and primers, cap-
type, are included, even though
they do not contain primary
explosives..Propellant explosive substance or C 1.1C
other deflagrating explosive 1.2C
substance or article containing 1.3C
such explosive substance. 1.4CSecondary detonating explosive D 1.1D
substance or black powder or 1.2D
article containing a secondary 1.4D
detonating explosive substance, 1.5D
in each case without means of
initiation and without a
propelling charge, or article
containing a primary explosive
substance and containing two or
more effective protective
features.Article containing a secondary E 1.1E
detonating explosive substance, 1.2E
without means of initiation, with 1.4E
a propelling charge (other than
one containing flammable liquid
or gel or hypergolic liquid).Article containing a secondary F 1.1F
detonating explosive substance 1.2F
with its means of initiation, 1.3F
with a propelling charge (other 1.4F
than one containing flammable
liquid or gel or hypergolic
liquid) or without a propelling
charge.Pyrotechnic substance or article G 1.1G
containing a pyrotechnic 1.2G
substance, or article containing 1.3G
both an explosive substance and 1.4G
an illuminating, incendiary, tear-
producing or smoke-producing
substance (other than a water-
activated article or one
containing white phosphorus,
phosphide or flammable liquid or
gel or hypergolic liquid).Article containing both an H 1.2H
explosive substance and white 1.3H
phosphorus.Article containing both an J 1.1J
explosive substance and flammable 1.2J
liquid or gel. 1.3JArticle containing both an K 1.2K
explosive substance and a toxic 1.3K
chemical agent.Explosive substance or article L 1.1L
containing an explosive substance 1.2L
and presenting a special risk 1.3L
(e.g., due to water-activation or
presence of hybergolic liquids,
phosphides or pyrophoric
substances) needing isolation of
each type.Articles containing only extremely N 1.6N
insensitive substances.Substance or article so packed or S 1.4S
designed that any hazardous
effects arising from accidental
functioning are limited to the
extent that they do not
significantly hinder or prohibit
fire fighting or other emergency
response efforts in the immediate
vicinity of the package.------------------------------------------------------------------------
Table 2--Scheme of Classification of Explosives, Combination of Hazard Division with Compatibility Group----------------------------------------------------------------------------------------------------------------
Compatibility group
Hazard division ---------------------------------------------------------------------
A B C D E F G H J K L N S A-S----------------------------------------------------------------------------------------------------------------1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 ... 1.1 ... 1.1 ... ... 9
A B C D E F G J L1.2 ... 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 ... ... 10
B C D E F G H J K L1.3 ... ... 1.3 ... ... 1.3 1.3 1.3 1.3 1.3 1.3 ... ... 7
C F G H J K L1.4 ... 1.4 1.4 1.4 1.4 1.4 1.4 ... ... ... ... ... 1.4 7
B C D E F G S1.5 ... ... ... 1.5 ... ... ... ... ... ... ... ... ... 1
D1.6 ... ... ... ... ... ... ... ... ... ... ... 1.6 ... 1
N
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Total 1 3 4 4 3 4 4 2 3 2 3 1 1 35---------------------------------------------------------------------------------------------------------------- [Amdt. 173-224, 55 FR 52617, Dec. 21, 1990, as amended by Amdt. 173-241, 59 FR 67492, Dec. 29, 1994; 64 FR 51918, Sept. 27, 1999; 66 FR 45379, Aug. 28, 2001; 76 FR 56315, Sept. 13, 2011; 78 FR 1074, Jan. 7, 2013]