The rapid spread of the COVID-19 worldwide pandemic at the beginning of 2020 has significantly affect-ed the global economy with severe human and economic losses. Despite the shortage of personal protective equipment, the facemask serves as a fundamental means to protect health care professionals' and re-strict the spread of the coronavirus. However, due to the limited stock of facemasks, many sterilization methods were developed to eliminate the infection and established strategies for fast and repeated reuse without affecting the filtration efficiency. The current study extrapolates the effective utilization of the ozonic sterilization of the N95 mask. First, we demonstrated the potential of ozone as a disinfectant that successfully destructs the organic food colour compounds deposited on the N95 mask; In the quantitative part of this research, the N95 facemask pieces were soaked in diphenylamine solution and later oxidized with ozone under the different intervals of time. Finally, the different standards of diphenylamine and methanol solution were calibrated under the spectrometric analysis to quantify the amount of the oxidized product present in the methanol solvent. The results show that ozone disinfectant has a significant potential to sterilize the mask, recover the cost-effective reuse, and can generate a comparable result equivalent to the other high-cost techniques. Furthermore, it was observed that the sample's ozone expo-sure time and accurate calibration are vital to influence the organic species' oxidization and accurately quantify the oxidized amount.