Experimental Study
FANG Qiong - qiong, WANG Jin, XIAO Xiao, GAO Di, TONG Ying, YU Li
Objective To investigate the physicochemical properties, disinfection efficacy against indicator microorganisms, and corrosion effects on common metals of three sodium percarbonate-based disinfectants. Methods The active oxygen content, pH value and metal corrosiveness of the three sodium percarbonate disinfectants were measured. Their bactericidal efficacy was evaluated using the quantitative suspension test. Results The active oxygen content of disinfectant A, B and C were 13.2%, 12.1% and 8.93%, respectively. A and B met the standard requirements, while C fell below the standard. At active oxygen content of 1.0%, the pH values of A, B, and C were 10.23, 10.10, and 10.52. All three disinfectants showed no significant corrosiveness to stainless steel, aluminum, or copper, but exhibited slight corrosiveness to carbon steel. The killing log value (KL) against Escherichia coli of disinfectant B≥5.00 with 0.05% active oxygen content incubating for 30 min, against Pseudomonas aeruginosa needed 0.1% active oxygen content for 30 min, and against Staphylococcus aureus needed 0.6% active oxygen content for 15 min. Disinfectant A and C needed 45 min to reach KL≥5.00. For Candida albicans, all three disinfectants with 2.0% active oxygen content achieved KL≥4.00 after 15 min. B completely eliminated Candida albicans within 15 min, while samples A and C required 30 min for complete eradication. In the test against Bacillus subtilis var. niger, all three disinfectants at 3.0% active oxygen content failed to reach KL≤5.00) after 120 min. Conclusion All three sodium percarbonate disinfectants can effectively killing bacterial propagules and fungi, but showed limited efficacy against spores and exhibited slight corrosiveness to carbon steel.