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

Abstract

After the outbreak of COVID-19, many dental clinics use dry fogging of hydrogen peroxide (H 2 O 2 ) to disinfect the air and surfaces. Inhalation of highly concentrated solutions of H 2 O 2 may cause severe respiratory problems. This study aimed to estimate the health risk assessments of inhalation exposure to dry fogging of H 2 O 2 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 H 2 O 2 in six rooms. Occupational exposure to H 2 O 2 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 4 collecting solution. The health effects of H 2 O 2 exposure were assessed using a respiratory symptoms questionnaire. The health risk assessment of inhaled exposure to H 2 O 2 was also performed using the method provided by the Singapore occupational health department. The mean respiratory exposure of clinic staff to H 2 O 2 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.

Inhalation Pneumonitis Caused by Nebulized Hydrogen Peroxide

“…Chronic inhalation of hydrogen peroxide is described as causing interstitial lung disease, with radiographic images demonstrating septal line thickening, honeycombing, and traction bronchiectasis with associated ground glass opacification [19]. In an observational study of dental clinic workers that use dry fogging of hydrogen peroxide to disinfect surfaces, some developed symptoms, including dyspnea, cough, and nasal burning at an average hydrogen peroxide concentration of 1.3 to 2.83 parts per million in room air [20].…”

Hydrogen peroxide emissions from surface cleaning in a single-family residence

“…9,10 Hydrogen peroxide has long- and short-term exposure limits of 1 and 2 ppmv, respectively, 11 with potential exposure effects including irritation and inflammation of mucous membranes. 12 Although H 2 O 2 appears to be a safer alternative to bleach for routine surface cleaning, gas-phase concentrations of H 2 O 2 during cleaning activities are largely unknown. In addition to direct exposure risks, H 2 O 2 can undergo gas-phase reactions such as photolysis to form reactive hydroxyl radicals (OH).…”