# An Overview of Tools and Challenges for Safety Evaluation and Exposure Assessment in Industry 4.0
## 3 Industry 4.0 Safety and Exposure Assessment Tools
### Occupational Safety Technologies  
In recent years, the concepts and technologies developed within the Industry 4.0 framework have been employed in health and safety sectors via predictive modelling and the development of innovative solutions focusing on employee safety in an occupational environment. Figure 3 depicts the increasing number of research publications (original articles, reviews, and conference proceedings) over the last decade obtained by using \"Industry 4.0\" as a keyword in the Web of Science platform. These numbers reflect the attention of Industry 4.0 solutions and technologies and ongoing research for the optimisation of existing solutions and development of innovative systems. At the same time, studies on the application of Industry 4.0 technologies as health and safety solutions, obtained by using both \"Industry 4.0\" and \"Safety\" as keywords in the Web of Science platform, projects at an increasing pace but at a lower magnitude; approximately 7% of the published papers on the Industry 4.0 subject over the last 5 years refer to the development of safety solutions and devices. Although the described analysis was based solely on a single academic journal search engine, it highlights the limited research on the exploitation of innovative and digitisation technologies for risk minimisation and safety improvements in the occupational workplace. Emerging technologies developed and employed as part of \"smart factories\" have been investigated in the literature to mitigate and prevent occupational risks. The use of virtual simulation via DT and autonomous robotic systems and advanced manufacturing technologies can reduce the human presence in dangerous occupational environments [49; 50]. The use of smart sensors and IoT applications allows for the continuous monitoring of the indoor environment quality (dust, humidity, noise, temperature, etc.) [12; 51; 52]. The use of wearable devices and data analytics of several well-being factors--such as fatigue, heart rate, etc.--through ML algorithms can lead to predictive modelling and instigate the development of smart personal protective equipment to prevent accidents in the workplace [53; 54; 55]. Proper implementation planning has been investigated to enhance the adoption of technologies in the workforce, increase safety in the occupational environment and minimise any negative effects arising from potential stress due to the increased complexity of manufacturing tasks and discomfort [56]. In particular, VR/AR systems have been investigated as training platforms for new employees that can highlight ergonomic issues and reduce accidents [57; 58]. At the same time, AR technologies coupled with AI  
Figure 2: Technologies and manufacturing systems described within Industry 4.0.  
solutions and real-time data analytics can lead to rapid data exchange and prevent actions, minimising occupational risks during operation, maintenance, and complex tasks [59]. Following the guidelines of a hierarchical hazard control--as also outlined in the ISO 45001 for the design of a health and safety management system--the tools of Industry 4.0 can be adopted in almost all aspects of hazard control and risk prevention. In detail, the hierarchy of control schemes presents a series of measures from the most to the least effective, namely elimination of hazard (removing the hazard), substitution (replacement with less hazardous options), engineering controls (isolation from the hazard), administrative controls (training and risk awareness), and PPE [60]. DT systems can be expressed as an engineering control system since they provide an exemplary tool for process isolation, where operators are not present in the physical environment and simulations and controls can be performed, checked, and optimised in the virtual domain. Similarly, the use of AR technologies coupled with AI analytics can be described as real-time automated engineering controls.