Quality control is indispensable for automated dilution systems with accelerated hydrogen peroxide

Hamilton Health Sciences (HHS) is a large teaching hospital with over 1000 beds consisting of three acute care sites, one regional cancer center and two rehabilitation/complex chronic care facilities. The use of chemical dilution control systems to dilute concentrated accelerated hydrogen peroxide (AHP) disinfectant to an ideal strength for effective environmental decontamination is a growing trend in healthcare. These systems, compared to manual dilution methods, are economical, efficient and promote a safer workplace. However, quality control (QC) and preventative maintenance standards to ensure performance are lacking in the environmental and healthcare cleaning industries. The automated systems used to dilute concentrated AHP products for disinfection cleaning were assessed for reliability at HHS-Henderson acute care site.

The control systems used on three clinical units to dilute concentrated AHP products, 7% Percept at 1:16 dilution (0.5%) and 3% PerDiem at 1:256 dilution (0.01%), were evaluated daily for reliability over 30 days. Virox AHP indicator test strips were used once a day to check use-dilution of Percept at 5000 parts per million (ppm) AHP and PerDiem at 100 ppm AHP.QC was repeated if the initial test was outside the acceptable range. Vendor service was arranged for the dilution system when repeat QC failed. Ready-to-use AHP product was employed until the system was functional.

Overall, nine QC failures were detected on all systems during a 30-day testing period, specifically, five failures on one system, three on the second and one on the third. Seven failures involved Percept with results at < or =500 ppm, well below the acceptable 5000 ppm concentration, and two involved PerDiem at 500 ppm, well above the required concentration.

Disinfectants must be used in the dilution specified by the manufacturer for optimal decontamination. Although there are benefits with using automated dilution systems in healthcare settings, findings show that attention must be given to quality control and preventative maintenance to ensure optimum results.