Near-source hypochlorous acid emissions from indoor bleach cleaning

Abstract

Cleaning surfaces with sodium hypochlorite (NaOCl) bleach can lead to high levels of gaseous chlorine (Cl2) and hypochlorous acid (HOCl); these have high oxidative capacities and are linked to respiratory issues.

Development and validation of a new in situ technique to measure total gaseous chlorine in air

“…The wavelengths monitored have been altered to selectively detect HOCl. Details on instrument calibration and validation are provided in Stubbs et al (2023).…”

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

“…In some cases, surfaces only a few meters apart resulted in total emissions at the detector inlet that varied by over a factor of 4. As discussed in the context of HOCl emitted from cleaning with NaOCl bleach, 19 people who are closer to cleaned surfaces (such as those doing the cleaning or children and animals whose faces are generally closer to the floor than those of adults) may be exposed to much higher levels of emissions from cleaning products than others in the same room. On a more hopeful note, our results also indicate that exposure can be minimized by leaving the area immediately after cleaning a surface.…”

“…We recently investigated the spatial and temporal variability of gas-phase hypochlorous acid (HOCl) following bathroom surface disinfection with a commercial sodium hypochlorite bleach spray. 19 In that work, HOCl was determined to be well-mixed at distances at least 160 cm from the surface, while air sampled within ∼60 cm of the surface was determined to be poorly mixed. This poor mixing was evidenced by a strong distance dependence for both peak HOCl concentrations and HOCl decay rate constants at short distances from the cleaned surfaces contrasted with a lack of distance dependence further from the surface.…”

“…Finally, recent studies have highlighted the spatial heterogeneity of indoor trace gases and aerosols (either directly emitted or formed via chemical reactions). [16][17][18][19] Marked differences in H 2 O 2 levels may be expected throughout the air volume of a residence. This work presents the rst study on the effects of the factors listed above on H 2 O 2 mixing ratios in a real, occupied residence during surface cleaning with an H 2 O 2 -based cleaner.…”

Antimicrobial efficacy, mode of action and in vivo use of hypochlorous acid (HOCl) for prevention or therapeutic support of infections

“…To test the upper limit of safe exposure, human cells can be stress tested with HOCl solutions of different concentrations to determine the limits of their physiological resilience. There are numerous works on this in the more recent literature [ 3 ], [ 33 ], [ 34 ], [ 35 ], [ 74 ], [ 75 ], [ 76 ], [ 77 ]. Further resources can be found in toxicology databases [ 78 ].…”