Actually, 1.4S is a shipping and storage category for hazardous materials. 1.4 S represents small arms ammunition.
Division 1.4 refers to the specific nature of the ammunition, and the suffix "S" refers to the packing, as follows:
Articles and substances that present no significant hazard. This division comprises articles and substances, which present only a small hazard in the event of ignition or initiation during transport. The effects are largely confined to the package and no projection of fragments of appreciable size or range is to be expected. An external fire must not cause virtually instantaneous explosion of almost the entire contents of the package. [b][i](i.e., is not prone to mass detonation)[/i][/b]
Note: Articles and substances in this division are placed in Compatibility Group S when they are so packed or designed that any hazardous effects arising from accidental functioning are confined within the package unless the package has been degraded by fire, in which case all blast or projection effects are limited to the extent that they do not significantly hinder fire-fighting or other emergency response efforts in the immediate vicinity of the package.
There is also a UN designation:
United Nations UN 0012 (below the 1.4S diamond)
UN 0012 defines the category ‘Cartridges for weapons, inert projectile or Cartridges, small arms’, being “Ammunition consisting of a cartridge case fitted with a centre or rimfire primer and containing both a propelling charge and solid projectile(s). They are designed to be fired in weapons of calibre not larger than 19.1 mm. Shotgun cartridges of any calibre are included in this definition.”
United Nations UN 0014
UN 0014 defines the category 'Cartridges for weapons, blank or Cartridges, small arms
All hazardous materials have similar category designations. UN designators are quite specific, covering almost every type of munition and explosive. For example UN 0055 describes empty primed cartridge cases and UN 0033-35 covers explosive bombs.