Sterilization Efficiency of Hypochlorous Acid is 50 to 80 times of Sodium hypochlorite (theoretical value)

Hypochlorous acid (HClO) is a strong sterilant and stable, while hypochlorite ion (OCl^-) has a low sterilization effect and is unstable. Comparing the sterilization power of these two, the bactericidal power of HClO can reach as much as 80 times that of OCl^-. (Please refer to the graph following)

Sterilization Efficiency Measurement Ex. the E. Coli killing time while chlorine is 0.1mg/L HClO about 1.5 minute (80 times)/td> OCl- abuot 120 minute (considered as 1 time) From the graph left, when the chlorine concentration is 0.1ppm, hypochlorous acid kills 99% of the E. Coli in only 1.5 minute, while hypochlorite ion needs 120 minutes. Source: Techlonogy of Purifiying Water

The time (in minute) for killing 99% of E. Coli E. Coli (minute) at water temperature 2~6℃

The table below shows the relations among that sodium hypochlorite. its pH value, and the consistence rate of HClO

=> while sodium hypochlorite at 4,000ppm (calculate at the optimum level) contains 24ppm of hypochlorous acid (HClO) and 3,976ppm of hypochlorite ion (OCl^-)

=> Total sterilization point is 73.7 points

As the hypochlorous acid water consists of 100％ HClO, when the hypochlorous acid reaches 80ppm, its sterilization points reaches 80 points.

※ Reference：Tanbo Norihito & Ogasawara Yuichi. Water Purification Technology. Gihodo Shuppan 1985