Chlorine Disinfection Time Table
Time table for killing common illness-causing germs
Free chlorine at neutral pH kills most bacteria such as E. coli 0157:H7 in less than a minute if the free chlorine is maintained at proper disinfection levels throughout the pool. However, a few germs are moderately (Giardia, Hepatitis A) to highly (Cryptosporidium) chlorine-resistant. The table below shows the approximate disinfection times for these germs in chlorinated water.
Agent | Disinfectant Times for Fecal Contaminants in Chlorinated Water* |
E coli 0157:H7 Bacterium |
< < 1 minute |
Hepatitis A Virus |
approximately 16 minutes |
Giardia Parasite |
approximately 45 minutes |
Cryptosporidium Parasite |
approximately 15300 minutes (10.6 days) |
|
Content Source:
Division of Parasitic Diseases
National Center for Zoonotic, Vector-borne, and Enteric Diseases
Page last modified: July 17, 2008
Division of Parasitic Diseases
National Center for Zoonotic, Vector-borne, and Enteric Diseases
Page last modified: July 17, 2008