Microbial Contamination of Antiseptics and Disinfectants
Somwang Danchaivijitr MD*, Chertsak Dhiraputra MD**, Yong Rongrungruang MD*, Nitaya Srihapol RN***, Varaporn Pumsuwan MSc***
Affiliation : *Department of Medicine, **Department of Microbiology ***Center for Nosocomial Infection Control, Faculty of Medicine Siriraj Hospital, Mahidol University
Objective : To study the bacterial contamination of antiseptics and disinfections in-use and the risk factors for
contamination.
Materials and Methods : Bacterial contamination of antiseptics and disinfectants was done by culturing in-use
solutions. Eight commonly used solutions were studied : alcohol 70%, chlorhexidine 4%, and 0.5%, povidone
iodine 7.5% and 10%, tincture iodine 1-2%, lysol 2% and sodium hypochlorite 0.5%.
Results : The following risk factors for contamination were found : preparation by unskilled personnel,
improper containers and prolonged use. Contamination with bacteria were found in 1.8% of 16,142 samples
tested. Highest rate of contamination was found in Lysol 2%. There was no contamination of povidone iodine
10% and tincture iodine 1-2%. Bacterial contamination of antiseptics and disinfectants was highest in
provincial hospitals and was not found in university hospitals. The rates of contamination correlated with the
duration of use. Most bacteria isolated were those found in the environment.
Conclusion : The contamination of in-use antiseptics and disinfectants was as high as 1.8%. Risk factors for
contamination were improper preparation and prolonged use.
Keywords : Contamination, Antiseptic, Disinfectants
