# Analysis of Research Hotspots and Trends in Confined-Space Work Safety Based on CiteSpace
## 3 Results
### Research Hotspots
#### 3.6.3 Keyword Bursting Analysis  
Keyword bursting analysis is a method by which CiteSpace software identifies hot keywords in the research frontier based on the growth rate of keyword frequency. Figures 12 and 13 illustrate the duration of the top 20 research hotspots in the Chinese and English-language literature from 2000 to 2023. In these figures, \"Year\" represents the year when the keyword first appeared, \"Strength\" represents the bursting intensity (with greater intensity indicating a higher influence [49]), and \"Begin\" and \"End\" represent the starting and ending years of the keyword as a frontier hotspot, respectively. The light blue represents the entire timeframe of the search analysis and the navy blue area of the bursting map represents the overall time range of the keyword, while the red area highlights the duration during which the keyword was considered a research hotspot. The Chinese literature mapping is mainly divided into three stages:  
Figure 11: Time-series plot of keyword clustering in the English-language literature.  
Figure 12: Bursting map of keywords in the Chinese literature.  
From 2006 to 2012, the main research directions were hazard analysis, accident prevention, and accident analysis of confined-space work. Key hot keywords during this period included \"preventive measure\", \"occupational poisoning\", \"hierarchical analysis\", \"safety countermeasure\", \"dangerous operation\", \"accident\", and \"control measure\". The release of the Safety Regulation for Working Under Hazardous Conditions of the Oxygen Deficiency (hereinafter referred to as the \"Safety Regulation\") in 2006 drew significant attention to preventive measures in confined spaces. Notably, the keyword \"accident\" was most prominent in 2012, reflecting a surge in research analyzing preventive measures based on accident cases in confined spaces.  
From 2013 to 2017, the research hotspots shifted towards the detection and ventilation of toxic and harmful gases in confined spaces, with a focus on the keywords \"detection\", \"ventilation\", and \"rescue\". This shift was influenced by the issuance of the Interim Provisions on Safety Management and Supervision of Confined Space Operation in Industry and Trade Enterprises, as well as the Five Regulations for Confined Space Work Safety in 2013, marking the first departmental regulations on confined-space work safety in China. These regulations standardized confined-space operations, emphasizing the need for detection and ventilation before work to address the main risks of poisoning and asphyxiation.  
From 2018 to 2023, the research primarily focused on prevention and control measures during confined-space work, with particular attention to chemical enterprises. Hot keywords during this period included \"countermeasures\", \"operators\", and \"chemical enterprises\". The prominence of \"chemical enterprises\" since 2020 suggests that this may be a future research hotspot and trend in confined-space work safety.  
In the keyword bursting map of the English literature, the keyword with the highest intensity is \"design\", which primarily focuses on reducing confined-space hazards through improved design. Overall, the bursting intensity of keywords in the English literature is not high. The research hotspots generally center on confined-space risk analysis, risk reduction, and occupational safety.  
Figure 13: Bursting map of keywords in the English-language literature.