## 1 Introduction
The current classification of natural hazards [4] no longer lists this hazard as a natural one.\"
* Water hazard--\"A natural hazard that may occur in mines due to the unexpected intrusion of water into workings from underground or surface reservoirs.\"
* Explosion hazard--\"A natural hazard in mines related to the explosion of gases and, in coal mines, coal dust explosions, which can be triggered by faulty electrical equipment (sparking) or other factors (e.g., blasting operations).\"  
The characteristics of natural hazards in coal mines have been described in several studies [17], covering the following risks:  
* Rock bursts;
* Gas hazard;
* Dust hazard;
* Water hazards;
* Roof collapses;
* Endogenous fires;
* Combined hazards;
* Technical hazards. It is important to note that numerous publications [6; 8; 17; 18; 19; 20; 21; 22; 23] discuss natural mining hazards not only listed in legal requirements [23] but also other significant risks. These include endogenous fire hazards, which arise from the natural tendency of coal to spontaneous combustion [24; 25]; combined hazards, resulting from the interaction between different natural hazards [17; 24; 25; 26; 27]; and gaso-geodynamic hazards, recently defined as a combination of rock burst and methane hazards [21]. The characteristics of occupational hazards in mining have been extensively discussed in various publications [17; 28]. The main sources of hazards are categorized into five key factors: physical, chemical, biological, ergonomic, and psychosocial hazards. For the mining industry, the most characteristic hazard groups include traumatic hazards (with natural hazards), ergonomics-related hazards [29; 30], noise exposure, and psychosocial hazards. Natural hazards, along with those resulting from work processes, mechanization, and work organization in mining, are most commonly classified into three main groups [24]:  
* Natural hazards;
* Technical hazards;
* Human-related hazards. The hazard identification stage is considered a critical step in the overall risk assessment process. This stage involves the use of both formal and informal techniques [31; 32] to recognize potential risks, which is referred to as hazard characterization. Informal techniques include:  
* Workplace observations;
* Interviews;
* Occupational health and safety (OHS) committee meetings;
* Professional experience;Employee consultations;
* Safety audit results. Some authors [33] emphasize, however, that relying solely on employees' knowledge and experience--an informal approach to hazard identification--does not ensure that hazards will be correctly recognized. Therefore, it is crucial to employ formal hazard identification methods [31] specifically designed for this process. Other researchers [34] have developed a catalog of 250 potential hazards for workers in gold mines and applied the multi-criteria AHP (Analytic Hierarchy Process) method in the occupational risk assessment process [34; 35]. The developed catalog [34] could also be useful in hazard identification processes in hard coal mining. Furthermore, the literature [1] highlights several frequently recurring hazards, including those associated with machinery, falls from height, workplace cleanliness, material storage, movement through mine roadways, and hazardous substances--all of which should not be overlooked in the hazard identification process. In summary, in the hazard identification process in the workplace, it is essential to consider all the discussed registers, lists, catalogs, and classifications. The main objective of the presented study is to develop a structured classification of occupational hazard factors that can support the identification, analysis, and assessment of risk, as well as the planning of preventive measures in the hard coal mining industry.