###### Abstract  
Background: The contamination of ambulances with pathogenic agents represents a potential threat for the public health, not only for common pathogens but also for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The aim of this project was to exploits the germicidal effect of the UVC radiation at 254 nm to sanitize the patient's compartment of ambulances with an advanced UltraViolet SANitizing System (UV-SAN) and assess its relevance for avoiding the spread of COVID-19 and other drug resistant pathogens. Methods: The system is equipped with UVC lamps that are activated when the ambulance compartment is empty and sanitize the environment in less than 15 min. An Ozone sensor continuously monitors the gas concentration, ensuring it does not exceed threshold value harmful for patients and operators' health. The system is relying on GNSS data and a satellite communication link, which allow to monitor and record traceability (when, where and what) of all the sanitation operations performed. This information is real-time monitored from a dedicated web-application. Results: UVC irradiation efficiently reduced SARS-CoV-2 virus titer (>99.99%), on mainnate surfaces such as plastic, stainless steel or rubber, with doses ranging from 5.5 to 24.8 mJ/cm\({}^{2}\) and the UV-SAN system is effective against multi drug resistant (MDR) bacteria up to >99.99%, after 10 to 30 min of irradiation. Conclusions: UV-SAN can provide rapid, efficient and sustainable sanitization procedures of ambulances. U 2021 19 2021  
hours on surfaces where deposited [3; 4; 5]. The COVID-19 pandemic has highlighted how sanitizations carried out correctly and repeatedly over time are a fundamental weapon to reduce the spread of pathogens in all environments and in particular healthcare ones. Contagion can be caused by contact with contaminated surfaces with SARS-CoV-2 and then touching facial areas. Not all infected people develop obvious symptoms [6]. Most infected people (81%) develop mild to moderate symptoms (up to mild pneumonia), 14% develop severe symptoms (dyspnoea, hypoxia or lung involvement greater than 50% on imaging), and 5% suffer from critical symptoms (respiratory failure, shock or multi-iorgan dysfunction) [7]. Especially older people or those with other co-morbidity are at greater risk of developing severe symptoms. Eliminating the risk of contagion is of fundamental importance, as the virus is able to survive on plastic and steel surfaces for up to 3 days ([[https://www.who.int/publications/m/item/first-data-on-stability-and-resistance-of-sars-coronavirus-compiled-by-members-of-who-laboratory-network](https://www.who.int/publications/m/item/first-data-on-stability-and-resistance-of-sars-coronavirus-compiled-by-members-of-who-laboratory-network)]([https://www.who.int/publications/m/item/first-data-on-stability-and-resistance-of-sars-coronavirus-compiled-by-members-of-who-laboratory-network](https://www.who.int/publications/m/item/first-data-on-stability-and-resistance-of-sars-coronavirus-compiled-by-members-of-who-laboratory-network))) (accessed on 22 December 2021), depending on the temperature and light conditions [3; 8]. Pathogens inactivation by physical and chemical disinfectants can leave some residual contamination [9], suggesting that a multiple disinfectant approach with efficacy UVC radiation is prudent. Effectiveness of UVC against pathogens and different strains of airborne viruses has long been established [10; 11; 12]. In the last decade, several studies have demonstrated the effectiveness of UVC light in the inactivation of different strains of coronavirus [13]. Since human coronaviruses have similar genomic dimension, which is the key factor in radiation sensitivity [14], it is very likely that inactivation of SARS-CoV-2 requires similar timing for the same absorbed UVC light [13]. However, the key point is to apply UVC in such a way as to sanitize as effectively as possible by eliminating the remaining pathogens on all surfaces, including the most hidden ones.