Estimating the time-varying emission rate of peracetic acid.

This article focuses on estimating the evaporation rate constant (K) and time-varying mass emission rate of peracetic acid (PAA) to improve exposure modeling during surface disinfection tasks, particularly in healthcare settings. Using a small spill model and well-mixed room (WMR) dispersion model, the study found that the evaporation rate constant of PAA (mean K = 1.18 min⁻¹) did not significantly vary with environmental factors such as surface type, ventilation rate, or local wind speed. The first-order decay rate constant of PAA in air was determined to be 0.5 h⁻¹, corresponding to a half-life of 83 minutes, which is longer than previously reported. Model validation trials showed good agreement between predicted and measured PAA concentrations, indicating a high potential for worker overexposure under typical ventilation conditions, thus emphasizing the need for adequate exposure controls when using PAA as a general disinfectant.