Increasing disinfection efficacy of glutaraldehyde via chemical and physical enhancement

As a biocide, glutaraldehyde (GA) acts via a complex crosslinking mechanism and the 2%GA solution is one of the most popular high-level disinfectant solutions for medical instrument processing. However, it takes 4 hours to produce complete killing of 10 6 Bacillus subtilis var. niger spores. In this study, chemical and physical synergisms with 2%GA are evaluated for their enhancement of sporicidal efficacy, reduction of GA concentration and shortening of the use time. Findings based on the research performed in our labouratory: (1) Complete killing of 10 6 Bacillus subtilis var. niger spores was achieved in 2 hours when 2%GA was used in combination with either a cationic surfactant (two examples), (2) The complete destruction of HBsAg (Hepatitis B Surface Antigen) was demonstrated when 2%GA was used in combination with a cationic surfactant within 5 minutes (vs. 30 minutes without a surfactant). (3) Complete killing of 10 6 Bacillus subtilis var. niger spores was achieved in 4 hours when 1%GA only was used in combination with a catatonic surfactant. The reduced GA concentration benefits health care workers for the reduced tendency of causing allergic dermatitis and eye, respiratory irritation. (4) The combined synergisms from both chemical and physical means were investigated. Thus, the 2%GA in combination with a cationic surfactant, at 40°C with ultra sonication led to the complete killing of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Mycobacterium chelonae subsp.abscessus (all in 10 6 concentration); complete inactivation of Poliovirus-I [TCID 50 (Tissue Culture Infective Dose) × 10 6] and HBsAg within 5 min; killing of Bacillus subtilis var. niger spores in less than 10 minutes (10 3 concentration) or less than 30 minutes (10 6 concentration). (5) The above synergisms can be applied to endoscopes processing in shorter time. © 2007 American Chemical Society.