The pandemic of COVID-19 disease has brought many challenges in the field of personal protective equipment. The amount of disposable surgical masks (DSMs) consumed increased dramatically, and much of it was improperly disposed of, i.e., it entered the environment. For this reason, it is crucial to accurately analyze the waste and identify all the hazards it poses. Therefore, in the present work, a DSM was disassembled, and gravimetric analysis of representative DSM waste was performed, along with detailed infrared spectroscopy of the individual parts and in-depth analysis of the waste. Due to the potential water contamination by micro/nanoplastics and also by other harmful components of DSMs generated during the leaching and photodegradation process, the xenon test and toxicity characteristic leaching procedure were used to analyze and evaluate the leaching of micro/nanoplastics. Micro/nanoplastic particles were leached from all five components of the mask in an aqueous medium. Exposed to natural conditions, a DSM loses up to 30% of its mass in just 1 month, while micro/nanoplastic particles are formed by the process of photodegradation. Improperly treated DSMs pose a potential hazardous risk to the environment due to the release of micro/nanoparticles and chloride ion content
