pH and H ₂ O ₂ Concentration of Hydrogen Peroxide Disinfection Systems

Hydrogen peroxide disinfection has causec discomfort for some soft contact lens wearers even though the solution was neutralized properly. The discomfort could be due to the end‐point pH of the system used or the residua H 2 O 2 concentration. Using a digital pH meter and H 2 O 2 concentration detection strips, we measured the pH and H 2 O 2 concentration of seven different hydrogen peroxide disinfection systems over their recommended disinfection and neutralization cycles to determine their time courses and endpoint values. The final pH of the seven systems varied from 6.15 to 7.74 pH units. All systems resulted in residual H 2 O 2 concentrations below threshold values. These findings indicated that the final pH may be the cause of patient discomfort after hydrogen peroxide disinfection and neutralization.