Military

UN Storage Compatibility Groupings

Under the UNO system, there are 13 storage compatibility groupings, which further categorize Class 1 explosives by their form or composition, ease of ignition, and sensitivity to detonation.

• SCG A--Bulk-initiating explosives that have the necessary sensitivity to friction, heat, or percussion (shock) to make them suitable for use as initiating elements in an explosive train. A distinction is made between primary initiating explosives and nonprimary initiating explosives. Examples of primary initiating explosives are lead azide, lead styphnate, mercury fulminate, and tetracene. Examples of nonprimary initiating explosives are dry forms of cyclotetramethylene tetranitramine (HMX), cyclotrimethylene trinitramine (RDX), and pentaerythritol tetranitrate (PETN).
  
  
• SCG B--Detonators and similar initiating devices that do not contain two or more independent safety features. This group also consists of items that contain initiating explosives designed to initiate or continue the functioning of an explosives train. Examples are blasting caps, small arms primers, fuzes, and detonators of all types.
• SCG C--Bulk propellants, propelling charges, and devices containing propellant with or without their own means of initiation. Upon initiation, these items will deflagrate, explode, or detonate. Examples are single-, double-, and triple-base propellants; composite propellants; rocket motors (solid propellant); and ammunition with inert projectiles.
  
  
• SCG D--High explosives (HE) and devices containing HE without their own means of initiation and without a propelling charge. This group includes explosives and ammunition that can be expected to explode or detonate when any given item or component thereof is initiated. This group does not include devices containing initiating explosives with independent safety features. Examples are wet HMX, plastic-bonded explosives (explosives formulated with a desensitizing plastic binder), trinitrotoluene (TNT), and black powder.
  
  
• SCG E--Explosives devices that lack their own means of initiation but contain or have a propelling charge (other than one containing a flammable or hypergolic liquid). Examples are artillery ammunition, rockets, and guided missiles.
  
  
• SCG F--Explosives devices that have their own means of initiation and with or without propelling charge. Examples are grenades, sounding devices, and similar items with an in-line explosive train in the initiator.
  
  
• SCG G--Pyrotechnic materials and devices containing pyrotechnic materials. Examples are devices that, when functioning, result in illumination, smoke, or an incendiary, lachrymatory, or sound effect.
  
  
• SCG H--Ammunition containing both explosives and white phosphorus (WP) or other pyrophoric material. Ammunition in this group contains fillers that are spontaneously flammable when exposed to the atmosphere. Examples are WP, plasticized white phosphorus (PWP), or other ammunition containing pyrophoric material.
  
  
• SCG J--Ammunition containing both explosives and flammable liquids or gels. Ammunition in this group contains flammable liquids or gels other than those that are spontaneously flammable when exposed to water or the atmosphere. Examples are liquid- or gel-filled incendiary ammunition, fuel-air explosive (FAE) devices, flammable liquid-fueled missiles, and torpedoes.
  
  
• SCG K--Ammunition containing both explosives and toxic chemical agents. Ammunition in this group contains chemicals specifically designed for incapacitating effects more severe than lachrymation. Examples are artillery or mortar ammunition (fuzed or unfuzed), grenades, and rockets or bombs filled with a lethal or incapacitating chemical agent.
  
  
• SCG L--Explosives or ammunition not included in other SC/HC groups. This group includes explosives or ammunition with characteristics that do not permit storage with other similar or dissimilar materials. Examples are damaged or suspect explosives devices or containers, explosives that have undergone severe testing, fuel-air explosive devices, and water-activated devices. Also included are experimental explosives, explosives of temporary interest, newly synthesized compounds, new mixtures, and salvaged explosives, unless established asbeing compatible with the original materials. Types of explosives in this group presenting similar hazards may be stored together.
  
  
• SCG N--Hazard Division 1.6 ammunition containing only extremely insensitive detonating substances (IEDS). Examples are bombs and warheads. If dissimilar Group N munitions, such as MK 82 and MK 84 bombs, are mixed together and have not been tested to assure nonpropagation, the mixed munitions are considered to be Hazard Division 1.2, Storage and Compatibility Group D, for purposes of transportation and storage.
  
  
• SCG S--Explosives, explosives devices, or ammunition presenting no significant hazard. Explosives ammunition, so designated or packed that, when in storage, all hazardous explosives effects are confined and self-contained within the item or package. Materials in this group are such that an incident that destroys all items in a single pack will not be communicated to other packs. Examples are thermal batteries, cable cutters, explosive actuators, and other ammunition items packaged to meet the criteria of this group.