Clorox ③ - Clorox VS Electrolyzed Water

Clorox VS Electrolyzed Water

“Slightly acidic hypochlorous acid (HOCl) is a substance produced by the white blood cells of the human body, so it is harmless to the skin, etc., and its sterilizing and disinfecting power is 80 to 120 times that of Clorox.”

What does this mean? It’s about the hot electrolyzed water machine these days. It turns water into water with a disinfecting effect through electrolysis, and it’s harmless to the human body, so it can be used safely at home! So what exactly is electrolyzed water?

Electrolyzed water refers to an aqueous solution created through electrolysis (=electrolysis). These days, electrolyzed water refers to water that is produced by electrolyzing tap water or tap water with salt added at home to produce hypochlorous acid (HOCl) or sodium hypochlorite (NaOCl). Electrolyzed water is used for sterilization, cleaning, and deodorization.

Electrolyzed water is used for purposes such as sterilization, cleaning, and deodorization.

When tap water is electrolyzed in an electrolytic water generator, it reacts with the chlorine in the tap water to create hypochlorous acid water (HOCl). However, since the chlorine content of tap water is very small, the electrolyzed water made at home becomes slightly acidic hypochlorous acid water. Hypochlorous acid water is classified into strongly acidic hypochlorous acid water, weakly acidic hypochlorous acid water, and slightly acidic hypochlorous acid water depending on the acidity and available chlorine content. Among them, slightly acidic hypochlorous acid water has a wide range of sterilizing effects against bacteria, viruses, and algae, so it is widely used. It is a colorless liquid and is odorless or has a faint chlorine smell.

Chemical structure of hypochlorous acid (HClO)

In the industry, hypochlorous acid water is manufactured and sold using hydrochloric acid or brine, but it is not cheap. Since electrolytic water machines are expensive, products sold as electrolytic water are also quite expensive for the same reason.

Hypochlorous acid products on sale

Some electrolyzed water products even advise you to add salt to them for a more powerful cleaning effect.

Add salt for a more powerful wash.

Salt is used to supplement the lack of chlorine in tap water. When added in small amounts to tap water and then electrolyzed, it becomes a sodium hypochlorite solution. It is called sodium hypochlorite preparations and is a colorless or light greenish yellow liquid with a characteristic chlorine smell. This is the Clorox we know.

Reaction formula for electrolytic production of sodium hypochlorite

If it's a substance like Lux, is it really necessary to buy an expensive electrolytic water machine and make Clorox yourself?

Chemical Structure of Sodium Hypochlorite (NaClO)

Of course, you may have purchased an electrolytic water machine to only make hypochlorous acid water. So what is the difference between hypochlorous acid water and Clorox?

Hypochlorous acid (HOCl) is the most effective disinfectant among chlorine compounds and is known to be 80 to 120 times more effective than sodium hypochlorite (NaOCl). (For reference, ethanol also cannot penetrate thick protein cell membranes such as microbial spores or molds, so the range in which you can expect a sterilizing effect is narrow. Hypochlorous acid is a more effective disinfectant than ethanol.)

Hypochlorous acid is 80 to 100 times more effective at sterilizing than Clorox.

Here, sodium hypochlorite refers to hypochlorite ion (OCl-). Sodium hypochlorite reacts with water to form HOCl or OCl-, and this ratio changes reversibly depending on the pH. Clorox is an aqueous solution in which sodium hypochlorite is dissolved in water, with a pH of 10 or higher, and most of the chlorine exists in the form of OCl-. Since OCl- has a lower sterilizing effect than HOCl, the sterilizing power of Clorox can be said to be determined almost entirely by HOCl, and this is where the saying that hypochlorous acid water has a sterilizing effect tens to hundreds of times greater than Clorox comes from.

However, hypochlorous acid water is unstable and easily decomposes into water. If you make it at home and use it, it will not decompose, so it can be said that it is worth using an electrolytic water machine even if it is expensive, as long as it is safe and effective. However, hypochlorous acid water made at home is made by decomposing a small amount of chlorine in tap water, so it is difficult to expect sufficient sterilizing effect because the concentration is low to begin with. It means that it is expensive and not effective.

It is true that hypochlorous acid water is harmless to the human body. Hypochlorous acid is a substance that is naturally produced when white blood cells perform phagocytosis against pathogens, and is an important component of the innate immune system.

HOCl is a substance that the human body produces naturally to fight infection.

However, the non-toxicity is because hypochlorous acid water made with tap water at home has a low concentration. If hypochlorous acid is highly concentrated, it can cause chemical burns (Korea Central Disaster and Safety Countermeasures Headquarters · Central Accident Response Headquarters, 2020). Its use as an external disinfectant for skin is also restricted. The same goes for sodium hypochlorite. Therefore, it is not appropriate to use electrolyzed water on the skin. Although the concentration is low and there is no disinfection effect, if it is an effective concentration, it can irritate the skin, eyes, and respiratory tract, so spraying electrolyzed water in a sprayer is not recommended due to the risk of human exposure.

The method of spraying electrolyzed water with a concentration that has a disinfecting effect using a sprayer is not recommended.

In fact, the active ingredient of Clorox is also hypochlorous acid. Clorox is usually used in a diluted form, and when this happens, the pH drops and the rate of HOCl production increases. Clorox shows its maximum hypochlorous acid when the pH is 4.0 to 5.5, but chlorine can be released. Chloride ions (OCl-) are not without sterilization effects, and they have a synergistic effect with hypochlorous acid by inhibiting the growth of microorganisms and by the effect of redox potential. Therefore, the ideal pH for expecting a safe and effective sterilization effect is between pH 6 and 7, which is close to neutral, does not contain chlorine, and contains more than 90% hypochlorous acid and less than 10% hypochlorous acid ions (OCl-). In other words, in terms of disinfection effects in actual use, hypochlorous acid water and Clorox diluted solutions do not differ much.

HOCl reaches its maximum at pH 4–5 (left), but a safe and effective pH is between 6 and 7 (right).

Then what about residual pesticides? Can residual pesticides really be removed with electrolytic water?

Most pesticide ingredients are organic compounds, and since hypochlorous acid reacts with organic matter, it is true that electrolytic water has the effect of reducing residual pesticides (HANG QI 2013). However, even in this case, it is a result of available chlorine, and considering that the amount of available chlorine in electrolytic water that shows a sterilizing effect is over 50 ppm (J Food Science 2006), it is difficult to say that electrolytic water removes residual pesticides more effectively than tap water. This is because hypochlorous acid water made with tap water at home has a maximum of 2 ppm of available chlorine (Korea Consumer Agency 2020), so it is no different from plain water. In fact, most pesticide ingredients are decomposed by wind, rain, sunlight, microorganisms, oxygen in the air, etc., or decomposed on their own, and even if a small amount remains, they can be sufficiently removed with running water.

Hypochlorous acid has a deodorizing effect. This is because it removes the cause of the odor, which is the same principle as sterilization, and since the effective ingredient of bleach is hypochlorous acid, it has the same deodorizing effect as hypochlorous acid water. However, electrolyzed water made at home with tap water does not have a deodorizing effect for the same reason as above.

Conclusion

Hypochlorous acid water made to meet the effective chlorine standard by electrolysis is relatively safe (not completely non-toxic), has little odor, and has excellent disinfecting effects, but electrolyzed water made at home using tap water has a low concentration and has almost no disinfecting effect. Since hypochlorous acid easily decomposes and loses its effect, it is difficult to store and use slightly acidic hypochlorous acid water manufactured and sold to meet the standards in the industry for a long time. It is true that hypochlorous acid water decomposes and only water remains, but it is not intended to be used in a spray form or on the skin in the first place, and it is ineffective, so there is no point in spraying it. The usage of hypochlorous acid water is the same as Clorox. Clorox has a smell compared to hypochlorous acid water, can irritate the human body when used in excess, and has the inconvenience of having to be diluted, but it has the advantage of being inexpensive and being able to expect the same effect even with a small amount.