Segregation.

(a) General. (1) The requirements of this section apply to all cargo spaces on deck or under deck of all types of vessels, and to all cargo transport units.

(2) Segregation is obtained by maintaining certain distances between incompatible hazardous materials or by requiring the presence of one or more steel bulkheads or decks between them or a combination thereof. Intervening spaces between such hazardous materials may be filled with other cargo which is not incompatible with the hazardous materials.

(3) The general requirements for segregation between the various classes of dangerous goods are shown in the segregation table. In addition to these general requirements, there may be a need to segregate a particular material from other materials which would contribute to its hazard. Such segregation requirements are indicated by code numbers in Column 10B of the § 172.101 Table.

(4) Segregation is not required between hazardous materials of different classes which comprise the same substance but vary only in their water content (e.g., sodium sulphide in Division 4.2 or Class 8).

(5) Whenever hazardous materials are stowed together, whether or not in a transport unit, the segregation of such hazardous materials from others must always be in accordance with the most restrictive requirements for any of the hazardous materials concerned.

(6) When the § 172.101 Table or § 172.402 requires packages to bear a subsidiary hazard label or labels, the segregation appropriate to the subsidiary hazards must be applied when that segregation is more restrictive than that required by the primary hazard. For the purposes of this paragraph, the segregation requirements corresponding to an explosive subsidiary hazard are—except for organic peroxides which are those corresponding to Division 1.3—those for Division 1.4 (explosive) materials.

(7) Where, for the purposes of segregation, terms such as “away from” a particular hazard class are used in the § 172.101 Table, the segregation requirement applies to:

(i) All hazardous materials within the hazard class; and

(ii) All hazardous materials for which a secondary hazard label of that class is required.

(8) Notwithstanding the requirements of paragraphs (a)(6) and (a)(7) of this section, hazardous materials of the same class may be stowed together without regard to segregation required by secondary hazards (subsidiary risk label(s)), provided the substances do not react dangerously with each other and cause:

(i) Combustion and/or evolution of considerable heat;

(ii) Evolution of flammable, toxic or asphyxiant gases;

(iii) The formation of corrosive substances; or

(iv) The formation of unstable substances.

(9) Stowage in a shelter-'tween deck cargo space is not considered to be “on deck” stowage.

(10) Where the code in column (10B) of the § 172.101 Table specifies that “Segregation as for...” applies, the segregation requirements applicable to that class in the § 176.83(b) General Segregation Table must be applied. However, for the purposes of paragraph (a)(8) of this section, which permits substances of the same class to be stowed together provided they do not react dangerously with each other, the segregation requirements of the class as represented by the primary hazard class in the § 172.101 Table entry must be applied.

(b) General Segregation Table. The following table sets forth the general requirements for segregation between the various classes of hazardous materials. The properties of materials within each class may vary greatly and may require greater segregation than is reflected in this table. If the § 172.101 Table sets forth particular requirements for segregation, they take precedence over these general requirements.

Table 176.83(b)—General Segregation Requirements for Hazardous Materials [Segregation must also take account of a single secondary hazard label, as required by paragraph (a)(6) of this section.] Class 1.1 1.2 1.5 1.3 1.4 1.6 2.1 2.2 2.3 3 4.1 4.2 4.3 5.1 5.2 6.1 6.2 7 8 9 Explosives, 1.1, 1.2, 1.5 (*) (*) (*) 4 2 2 4 4 4 4 4 4 2 4 2 4 X Explosives, 1.3 (*) (*) (*) 4 2 2 4 3 3 4 4 4 2 4 2 2 X Explosives, 1.4, 1.6 (*) (*) (*) 2 1 1 2 2 2 2 2 2 X 4 2 2 X Flammable gases 2.1 4 4 2 X X X 2 1 2 X 2 2 X 4 2 1 X Non-toxic, non-flammable gases 2.2 2 2 1 X X X 1 X 1 X X 1 X 2 1 X X Poisonous gases 2.3 2 2 1 X X X 2 X 2 X X 2 X 2 1 X X Flammable liquids 3 4 4 2 2 1 2 X X 2 1 2 2 X 3 2 X X Flammable solids 4.1 4 3 2 1 X X X X 1 X 1 2 X 3 2 1 X Spontaneously combustible substances 4.2 4 3 2 2 1 2 2 1 X 1 2 2 1 3 2 1 X Substances which are dangerous when wet 4.3 4 4 2 X X X 1 X 1 X 2 2 X 2 2 1 X Oxidizing substances 5.1 4 4 2 2 X X 2 1 2 2 X 2 1 3 1 2 X Organic peroxides 5.2 4 4 2 2 1 2 2 2 2 2 2 X 1 3 2 2 X Poisons 6.1 2 2 X X X X X X 1 X 1 1 X 1 X X X Infectious substances 6.2 4 4 4 4 2 2 3 3 3 2 3 3 1 X 3 3 X Radioactive materials 7 2 2 2 2 1 1 2 2 2 2 1 2 X 3 X 2 X Corrosives 8 4 2 2 1 X X X 1 1 1 2 2 X 3 2 X X Miscellaneous dangerous substances 9 X X X X X X X X X X X X X X X X X Numbers and symbols relate to the following terms as defined in this section: 1—“Away from.” 2—“Separated from.” 3—“Separated by a complete compartment or hold from.” 4—“Separated longitudinally by an intervening complete compartment or hold from.” X—The segregation, if any, is shown in the § 172.101 table. *—See § 176.144 of this part for segregation within Class 1.

(c) Segregation requirements for breakbulk cargo. (1) The requirements of this paragraph apply to the segregation of packages containing hazardous materials and stowed as breakbulk cargo;

(2) Definition of the segregation terms:

(i) Legend:

(A) Package containing incompatible goods.

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(B) Reference package.

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(C) Deck resistant to fire and liquid.

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Note: Full vertical lines represent transverse bulkheads between compartments or holds resistant to fire and liquid.

(ii) “Away from”: Effectively segregated so that the incompatible materials cannot interact dangerously in the event of an accident but may be carried in the same compartment or hold or on deck provided a minimum horizontal separation of 3 m (10 feet) projected vertically is obtained.

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(iii) “Separated From”: In different compartments or holds when stowed under deck. If the intervening deck is resistant to fire and liquid, a vertical separation (i.e., in different compartments) is acceptable as equivalent to this segregation. For “on deck” stowage, this segregation means a separation by a distance of at least 6 m (20 feet) horizontally.

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(iv) “Separated by a complete compartment or hold from”: Either a vertical or horizontal separation. If the intervening decks are not resistant to fire and liquid, then only a longitudinal separation (i.e., by a intervening complete compartment or hold) is acceptable. For “on deck” stowage, this segregation means a separation by a distance of at least 12 m (39 feet) horizontally. The same distance must be applied if one package is stowed “on deck”, and the other one in an upper compartment.

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Note: One of the two decks must be resistant to fire and liquid.

(v) “Separated longitudinally by an intervening complete compartment or hold from”: Vertical separation alone does not meet this requirement. Between a package “under deck” and one “on deck” a minimum distance of 24 m (79 feet) including a complete compartment must be maintained longitudinally. For “on deck” stowage, this segregation means a separation by a distance of at least 24 m (79 feet) longitudinally.

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(d) Segregation in transport units: Two hazardous materials for which any segregation is required may not be stowed in the same transport unit.

(e) Segregation of hazardous materials stowed as breakbulk cargo from those packed in transport units: (1) Hazardous materials stowed as breakbulk cargo must be segregated from materials packed in open transport units in accordance with paragraph (c) of this section.

(2) Hazardous materials stowed as breakbulk cargo must be segregated from materials packed in closed transport units in accordance with paragraph (c) of this section, except that:

(i) Where “away from” is required, no segregation between packages and the closed transport units is required; and

(ii) Where “separated from” is required, the segregation between the packages and the closed transport units may be the same as for “away from”.

(f) Segregation of containers on board container vessels: (1) This paragraph applies to the segregation of freight containers which are carried on board container vessels, or on other types of vessels provided these cargo spaces are properly fitted for permanent stowage of freight containers during transport.

(2) For container vessels which have cargo spaces used for breakbulk cargo or any other method of stowage, the appropriate paragraph of this section applies to the relevant cargo space.

(3) Segregation Table: Table § 176.83(f) sets forth the general requirements for segregation between freight containers on board container vessels.

(4) In table § 176.83(f), a container space means a distance of not less than 6 m (20 feet) fore and aft or not less than 2.5 m (8 feet) athwartship.

Table 176.83(f)—Segregation of Containers on Board Container Ships Segregation requirement Vertical Closed versus closed Closed versus open Open versus open Horizontal Closed versus closed On deck Under deck Closed versus open On deck Under deck Open versus open On deck Under deck 1. “Away from” One on top of the other permitted Open on top of closed permitted Otherwise as for open versus open Not in the same vertical line unless segregated by a deck Fore and aft Athwartships No restriction No restriction No restriction No restriction No restriction No restriction No restriction No restriction One container space One container space One container space or one bulkhead.One container space. 2. “Separated from” Not in the same vertical line unless segregated by a deck As for open versus open Not in the same vertical line unless segregated by a deck Fore and aft Athwartships One container space One container space One container space or one bulkheadOne container space One container space One container space One container space or one bulkheadTwo container spaces One container space. Two container spaces. One bulkhead. One bulkhead. 3. “Separated by a complete compartment or hold from” Not in the same vertical line unless segregated by a deck As for open versus open Not in the same vertical line unless segregated by a deck Fore and aft Athwartships One container spaceTwo container spaces One bulkhead One bulkhead One container spaceTwo container spaces One bulkhead One bulkhead Two container spacesThree container spaces Two bulkheads. Two bulkheads. 4. “Separated longitudinally by an intervening complete compartment or hold from” Prohibited Fore and aft Athwartships Four container spaces Prohibited One bulkhead and four container spaces*Prohibited Four container spaces Prohibited Two bulkheads Prohibited Four container spaces Prohibited Two bulkheads. Prohibited. * Containers not less than 6 m (20 feet) from intervening bulkhead. Note: All bulkheads and decks must be resistant to fire and liquid.

(g) Segregation of transport units on board trailerships: (1) The requirements of this paragraph apply to the segregation of transport units which are carried on board trailerships or in “roll-on/roll-off” cargo spaces.

(2) For trailerships which have spaces suitable for breakbulk cargo, containers, or any other method of stowage, the appropriate paragraph of this section applies to the relevant cargo space.

(3) Segregation Table. Table § 176.83(g) sets forth the general requirements for segregation between transport units on board trailerships.

Table 176.83(g)—Segregation of Transport Units on Board Trailerships and Trainships. Segregation requirement Closed versus closed On deck Under deck Closed versus open On deck Under deck Open versus open On deck Under deck 1. “Away From” Fore and aft No restriction No restriction No restriction No restriction At least 3 m At least 3 m. Athwartships No restriction No restriction No restriction No restriction At least 3 m At least 3 m. 2. “Separated from” Fore and aft Athwartships At least 6 m At least 3 m At least 6 m or one bulkheadAt least 3 m or one bulkhead At least 6 m At least 3 m At least 6 m or one bulkheadAt least 6 m or one bulkhead At least 6 mAt least 6 m At least 12 m or one bulkheadAt least 12 m or one bulkhead 3. “Separated by a complete compartment or hold from” Fore and aft Athwartships At least 12 m At least 12 m At least 24 m + deck At least 24 m + deck At least 24 m At least 24 m At least 24 m + deck At least 24 m + deck At least 36 m At least 36 m Two decks or two bulkheads. Prohibited. 4. “Separated longitudinally by an intervening complete compartment or hold from” Fore and aft Athwartships At least 36 m Prohibited Two bulkheads or at least 36 m + two decksProhibited At least 36 m Prohibited At least 48 m including two bulkheadsProhibited At least 48 m Prohibited Prohibited. Prohibited. Note: All bulkheads and decks must be resistant to fire and liquid.

(h) Segregation on board barge carrying vessels: (1) The requirements of this section apply to the segregation in shipborne barges as well as to the segregation between shipborne barges carried on board vessels specially designed and equipped to carry such barges.

(2) On barge-carrying vessels which incorporate other stowage spaces or any other method of stowage, barges containing hazardous materials must be segregated from hazardous materials not stowed in barges as prescribed in paragraphs (b) and (j) of this section.

(i) Segregation in shipborne barges: Hazardous materials transported in shipborne barges must be segregated as prescribed in paragraphs (a), (b), and (c) of this section.

(j) Segregation between shipborne barges on barge-carrying vessels: (1) When a shipborne barge is loaded with two or more hazardous materials with different requirements for segregation, the most stringent applicable segregation requirement must be applied.

(2) “Away from” and “separated from” require no segregation between shipborne barges.

(3) For barge-carrying vessels with vertical holds, “Separated by a complete compartment or hold from” means that separate holds are required. On barge-carrying vessels having horizontal barge levels, separate barge levels are required and the barges may not be in the same vertical line.

(4) “Separated longitudinally by an intervening complete compartment or hold from” means, for barge-carrying vessels with vertical holds, that separation by an intervening hold or engine room is required. On barge-carrying vessels having horizontal barge levels, separate barge levels and a longitudinal separation by at least two intervening barge spaces are required.

(k) Segregation requirements for ferry vessels: A ferry vessel (when operating either as a passenger or cargo vessel) that cannot provide the separation required in this section may carry incompatible hazardous materials in separate transport vehicles if they are stowed to give the maximum possible separation.

[Amdt. 176-30, 55 FR 52690, Dec. 21, 1990, as amended at 56 FR 66282, Dec. 20, 1991; 57 FR 45465, Oct. 1, 1992; Amdt. 176-34, 58 FR 51533, Oct. 1, 1993; Amdt. 176-38, 60 FR 49111, Sept. 21, 1995; 64 FR 10781, 10782, Mar. 5, 1999; 66 FR 45184, 45384, Aug. 28, 2001]