Degradation of bleach produced for disinfection in Kenyan healthcare facilities using novel technology

Disinfection with bleach is recommended for surface cleaning in healthcare facilities, but bleach degrades over time, reducing disinfection effectiveness. We evaluated whether local bleach produced by hospitals using novel technology had adequate shelf life to justify use. Two hospitals (A and B) each produced and stored 0.5% bleach in two 20-liter plastic containers; bleach in one container was alkalinized for increased stability to pH 12; bleach in the other container was not stabilized and, for comparison, a third container of commercial bleach was tested. We tested three bleach samples from each of the containers produced by hospitals A and B, and commercial bleach for free available chlorine (FAC) using N,N-diethyl-p-phenylenediamine at irregular intervals up to 216 days. We compared the expected percent decrease in FAC per 7 days by bleach type using log-normal regression. Stabilized bleach decreased by 1% and 2% in hospitals A and B, respectively, every 7 days while non-stabilized bleach decreased by 21% and 12%, respectively (all p<0.001); commercial bleach decreased by <1% per 7 days. Bleach production proved feasible in hospitals, and both stabilized and commercial bleach maintained adequate concentration for disinfection; non-stabilized bleach maintains a useful concentration for not longer than three weeks after production.