Advancing the understanding of daily peracetic acid-based hospital surface disinfection and associated complaints of eye and respiratory irritation

Abstract

Peracetic acid (PAA)-based disinfectants for daily wipe-on cleaning of high touch hospital surfaces were deployed in the US since 2013 applying principles of the 2020 Centers for Disease Control ‘Core Components of Environmental Cleaning and Disinfection’ to optimize patient-zone environmental hygiene.  Large scale efficacy studies of PAA-based cleaning protocols at 8 US hospitals led to an average 50% decline in Clostridium difficile infection rates. Concurrent monitoring of cleaning protocol implementation validated by covert visual monitoring showed nearly doubled cleaning effectiveness. Concerns were raised about hospital worker eye and respiratory irritation complaints with these new PAA daily cleaning protocols. A rigorous human volunteer study was implemented to assess objective and subjective indicators of eye and respiratory inflammation in persons following PAA cleaning protocols in a controlled environmental chamber. Field studies identified upper bound cleaning parameters and mass transfer elements that were integrated into the environmental chamber study design. Among 44 volunteers (40 female) studied, the measured breathing zone concentrations of PAA, acetic acid (AA), and hydrogen peroxide (HP) and effect metrics (subjective eye, nose, throat, and odor ratings plus 15 objective metrics of eye and respiratory inflammation) were assessed in a within subject, double-blinded, crossover design involving eight 20-minute cleaning sessions per day: PAA mixture (3 trails), AA only (3 trials), HP only (1 trial) and water control (1 trial). Inhalation exposures for the PAA trials showed 95^th percentile concentrations of 101 ppb for PAA, 500 ppb for AA, and 667 ppb for HP. Subjective ratings were significantly greater for nose irritation and odor intensity versus eye or throat irritation, with the highest ratings for PAA > AA only >> HP only > water control. No significant increases were found for objective markers of tissue injury, inflammation, or allergic sensitization, and no frank signs of eye or respiratory inflammation were observed. Cluster analysis showed that persons giving the highest irritation ratings had significantly lower inhalation exposures during PAA mixture and AA only trials, suggesting use of avoidance behaviors to reduce perceived nasal irritation.  These studies advanced our understanding of exposures and potential adverse health effects of highly effective PAA disinfection protocols.