Health risk assessment of inhalation exposure to dry fogging of hydrogen peroxide in a dental clinic during the COVID-19 pandemic.

After the outbreak of COVID-19, many dental clinics use dry fogging of hydrogen peroxide (HO) to disinfect the air and surfaces. Inhalation of highly concentrated solutions of HO may cause severe respiratory problems. This study aimed to estimate the health risk assessments of inhalation exposure to dry fogging of HO in a dental clinic. This cross-sectional, descriptive-analytical study was performed to determine the inhalation exposure and health risk of 9 dental clinic staff with HO in six rooms. Occupational exposure to HO was assessed using the OSHA VI-6 method and a personal pump with the flow rate of 500 mL/min connected to the midget fritted-glass impinger containing 15 mL of TiOSO collecting solution. The health effects of HO exposure were assessed using a respiratory symptoms questionnaire. The health risk assessment of inhaled exposure to HO was also performed using the method provided by the Singapore occupational health department. The mean respiratory exposure of clinic staff to HO was ranged from 1.3 to 2.83 ppm for six rooms which was above the limits recommended by international organizations. Dyspnea (44.4%), cough (33.3%), and nasal burning (22.2%) were the most prevalent health problems. The results also showed a medium risk for endodontics and surgery, and lower risk for periodontics, restorative care, orthodontics, and prosthetics. The results of this study indicate that when using an automated hydrogen peroxide-vapor fogger, calculating the spraying time based on room volume and using the rooms after 30 min of fogging is very important and can greatly reduce the risk ranking.