UN/NA Identification Number : The four-digit number assigned to a hazardous material/weapon of mass destruction (WMD), which is used to identify and cross-reference products in the transportation mode
NFPA 472 Standard for Competence of Responders to Hazardous Materials/ Weapons of Mass Destruction Incidents, 2008 ed. http://www.dps.state.ak.us/afsc/docs/Certification /HazMatAwarenessSkillSheets.pdf, (Std: Competence of Resp to Haz Mtrl/ Weapons of Mass Destruction Incid - Amer) {318 NFC}