## 2 Overview of CBRN Agents  
CBRN agents are classified into many areas. The most general classifications divide them into substances used for combat purposes and those used in industries as toxic industrial materials (TIMs). It should be noted that the term TIMs is not synonymous with industrial chemicals (TICs), as it also includes toxic industrial biologists (TIBs) and toxic industrial radiologists (TIRs) [27]. Chemical agents can be categorized as TICs and chemical warfare agents (CWAs). Toxic industrial chemicals (TICs) include sulfur dioxide (SO2), hydrogen cyanide (HCN), hydrogen sulfide (H2S), ammonia (NH3), and chlorine (CI2) [28]. At the same time, chemical warfare agents (CWAs) encompass, for instance, cyclosarin (GF), VX (venomous agent X), tabun (GA), soman (GD), sarin (GB), and sulfur mustard (HD) [29]. Biological agents can be divided into categories A, B, and C. Category A agents are easily transmitted, resulting in high mortality, may cause public panic, and require extraordinary actions. Their examples are anthrax, smallpox, botulism, plague, tulareia, and viral hemorrhagic fevers. Category B agents are moderately easy to disseminate, result in moderate morbidity and low mortality rates, and require enhanced diagnostic capacity surveillance. They can be salmonella, typhus, or ricin. Category C agents are available everywhere, easy to produce and disseminate, and may result in high morbidity and mortality rates. They encompass the Nipah virus and hantavirus [30]. Regarding radiological agents, there are four major types of radiation: alpha (a relatively large subatomic particle--a helium nucleus, within a short range in the air, but it is potentially hazardous in the case of organism contamination); beta (relatively small subatomic particles consisting of electron/positron, within several meters range in the air); neutrons (connected to nuclear materials and the fission process, which are highly penetrating and vary in damage, depending on the energy of the neutrons); and gamma rays which penetrate intensely within a range of kilometers and consist of high-energy electromagnetic waves [31]. Apart from this general classification, there are other views. For instance, according to [PERSON] (2009), chemical agents include nerve agents (organophosphorus compounds), blistering agents (vesicants), cyanides (also known as blood agents), pulmonary agents (choking or lung-damaging agents), incapacitants (mental and physical), toxic industrial chemicals (TICs), riot-controlled agents (RCAs, used by law enforcement agencies), and pharmaceuticals (illicit and commercial drugs). Within biological agents, there are bacteria, including chlamydia and rickettsia, viruses, fungi, and toxins, which can be derived from bacteria, fungi, plants, and animals (venom). Concerning radiological and nuclear hazards, [PERSON] distinguishes four main types of radiation: alpha, beta, neutrons, and Gamma/X-ray radiation and notes that neutrons are usually only present during the nuclear process [32]. The classifications are not entirely clear because many substances that are warfare agents can also be used in industries and medicine, e.g., hydrogen cyanide (HCN), phospene (COCl2), and botulinum toxin. In addition, some plant protection products have a high level of toxicity, e.g., sarin. Therefore, the essential division category is the purpose and method of using these hazardous substances, which can be described as \"dual-use substances\". Regardless of intentional or accidental release, the characteristics above reveal the serious harms CBRN agents can cause to human health and the environment. This is due to the different persistence of a substance--it can disappear a relatively short time after exposure or remain in the environment for a longer time.