Water Treatment Are protozoa resistant to chlorine? March 2, 2026 by Myaya | Leave a Comment Protozoa are generally not resistant to chlorine, especially at sufficient concentrations and contact times. However, some protozoan cysts, like Cryptosporidium and Giardia, can exhibit partial resistance to chlorine disinfection, requiring higher doses or longer exposure to be effectively inactivated. This partial resistance means that standard chlorine treatments might not always guarantee complete elimination of these […] Read more ยป