46 AFMAN 24-204(I)/TM 38-250/NAVSUP PUB 505/MCO P4030.19H/ DLAI 4145.3 11 DECEMBER 2001 Figure A4.1.  Hazard Classes. HAZARD CLASS/ DIVISION NUMBER HAZARD CLASS/ DIVISION NAME HAZARD CLASS/ DIVISION NUMBER HAZARD CLASS/ DIVISION NAME     1.1 Explosives (with mass explosion hazard)     4.1 Flammable solid     1.2 Explosives (with a projection hazard)     4.2 Spontaneously combustible material     1.3 Explosives (with predominately a fire hazard)     4.3 Dangerous when wet material     1.4 Explosives (with no significant blast hazard)     5.1 Oxidizer     1.5 Very insensitive explosives; blasting agents     5.2 Organic peroxide     1.6 Extremely insensitive detonating substances     6.1 Poisonous (toxic) material     2.1 Flammable gas     6.2 Infectious substances (etiologic agents)     2.2 Nonflammable gas 7 Radioactive material     2.3 Poisonous gas 8 Corrosive material 3 Flammable liquid 9 Miscellaneous hazardous material A4.3.2.  Items Not Specifically Listed.  If a material is not specifically listed in table A4.1, determine the PSN by comparing the characteristics of the items with the definitions of the various hazard classes in this manual.  Assign a "Not Otherwise Specified" (N.O.S.) name based on the hazard class of the material.  Examples are: "FLAMMABLE LIQUID, N.O.S.; CORROSIVE SOLID, N.O.S."  Attachment 1 contains hazardous class definitions.  Determine the appropriate technical name according to A4.3.1. A4.3.3.  Tentative PSN Assignment.  A material for which the hazard class must be determined by testing,  or  a material that is a hazardous waste, the shipper may assign a tentative shipping name, based on: - The defining criteria of the hazard class. - The hazard precedence prescribed in A4.3. - The shipper’s knowledge of the material. - A3.3.1.2 for new explosives. - If a N.O.S. PSN is assigned, a technical name is not required. HA4.3.4  Precedence of Hazard.  Assign any material specifically identified and listed  in table  A4.1 the hazard class  identified  in  column 3  of  table  A4.1.    Classification  tools  identified in  A4.3.1  should  be  used  to  determine appropriate  hazardous  material  description.    If  required,  classify  a  hazardous  material  that  is  not  specifically identified and listed in table A4.1 (or is a mixture of materials), and meets the definition of more than one hazard, according to the following order of precedence: - Class  7  (Radioactive  material,  other  than  limited  quantities).    When  limited  quantities  are  involved  the other hazardous properties take precedence. - Class 1 (Explosives). - Class 2.3 (poisonous gas). - Class 2.1 (flammable gas).  See also Class 9. - Class 2.2 (nonflammable gas).  See also Class 9. - Class 5.2 (organic peroxide). - Class 6.2 (infectious substances or etiologic agents). - Class 4.1 (flammable solid).  Only self-reactive substances and wetted explosives. - Class 4.2 (substances liable to spontaneous combustion).  Only pyrophoric substances. - Class 6.1 (poisonous substances), PG I, poisonous by inhalation only. - Small quantities of compressed gas such as starter fluid (Class 2.1) or fire extinguisher (Class 2.2) installed on a vehicle do not take precedence over the flammable liquid (Class 3). - If required, classify other hazardous materials not identified above according to 49 CFR 173.2a