[Quality Control of Medical Instruments and Cleaning Water].

Purpose: Herein we aimed to investigate the degradation of surgical instruments in our hospital and how water quality affects the rate of metal corrosion.
Materials and Methods: We observed 279 stainless steel instruments, and determined the presence of damage like metal corrosion or scale formation. We also measured the concentrations of chloride(Cl ^- )and silicate(SiO ₄ ^4- )ions in the water used for cleaning in our operating rooms, including tap water from the city water supply and reverse-osmosis(RO)filtered water.
Result: Pitting corrosion was observed on 71% of the instruments we investigated. The concentration of Cl ^- was 0.7mg/L in tap water and 0.1mg/L in RO water, while the concentration of SiO ₄ ^4- was 0.3mg/L in both the tap and RO water.
Discussion: Of the dissolved ions Cl ^- and SiO ₄ ^4- , Cl ^- is more of a concern, as it causes pitting corrosion over time, while SiO ₄ ^4- causes scale formation. Considering the typical water quality in the operating-room environment, degradation must be monitored for the general maintenance of metal surgical instruments.