The Difference Between Calcium Hypochlorite and Sodium Hypochlorite

I. What is Calcium Hypochlorite?

Calcium Hypochlorite, which we often call it Cal Hypo in the industry, is an inorganic substance with the chemical formula Ca(ClO)2​    我 . The appearance of Cal Hypo is white or off-white granular with a strong smell. It could maintain stable chemical properties at room temperature, but in extreme environments such as high temperature and humidity, or in contact with organic matter and acids, it is easy to decompose oxygen and chlorine. 

So usually we would inform our customers that Calcium Hypochlorite should be keep away from trichlorine, and place it in a dry, dark space. And please remember, keep them away from your children! Chlorine is toxic and deadly, do not mix them with other chemicals, and please follow the instruction on the bucket label.

Also, it is highly oxidizing and is a important oxidant. It can redox with many reducing substances, for example, it can fade organic pigments and play a role in bleaching.

II. What is the usage of Calcium Hypochlorite? 

From Section One, we know that Calcium Hypochlorite is a strong oxidant, so one of its common uses is bleaching. A British chemist Tainet dissolved chlorine in lime milk to make bleaching powder, which is mainly composed of Calcium Hypochlorite and calcium chloride in 1789. Since then, Cal Hypo has been using as a essential bleach, and it has been in the industry for more than 200 years.

We all know that chlorine is one of the most popular element in disinfectant industry. And one of the main element of hypochlorite is chlorine, that’s why Cal Hypo is a commonly used disinfectant for drinking water, which can effectively kill bacteria, viruses and algae in the water to ensure the safety of drinking water. In swimming pool water treatment, Calcium Hypochlorite could also keep the water crystal clean.

III. What is Sodium Hypochlorite, and what’s the usage of it?

Same as Cal Hypo, Sodium Hypochlorite is an inorganic substance too, with a chemical formula NaClO, the form we often see is yellowish liquid, and it also has a strong smell like chlorine.

In 1785, French chemist Claude Louis Bertolet discovered that aqueous solutions of chlorine gas had bleaching properties, and for the first time, chlorine solutions were used to bleach paper and fabrics, and sodium hypochlorite solutions were prepared by introducing chlorine gas into a sodium carbonate solution. 

In 1822, LaBarac began selling Sodium Hypochlorite and Calcium Hypochlorite solutions for disinfection purposes in Paris. 

Since then, the application of Sodium Hypochlorite in the fields of bleaching and disinfection has gradually been developed and promoted. It has been in the industry for more than 200 years. 

So generally, it’s a common bleach and disinfectant in water treatment field, pretty the same with Calcium Hypochlorite.

IV. Calcium Hypochlorite vs Sodium Hypochlorite

From the three sections above, we learn about Calcium Hypochlorite and Sodium Hypochlorite, and also their main usages. Now, we must be wondering which one is better, or shall we say which one is more suitable.

Cal Hypo is often in solid form, while Sodium Hypochlorite is often in liquid form. From this aspect, Calcium Hypochlorite is more stable than Sodium Hypochlorite. Cal Hypo is easy to store in one’s house for a long time, while Sodium Hypochlorite decomposes more easily than Cal Hypo. Also, due to its excellent stability, Cal Hypo is safer to transport by sea. 

Ps: Commonly, a standard 20 ft. dry container could load around 14.805 tons of AGUACHLON Calcium Hypochlorite. 

Usually, when we talk about available chlorine, Calcium Hypochlorite is more superior than Sodium Hypochlorite. Nowadays, the usual available chlorine content of Calcium Hypochlorite is around 70%, but Sodium Hypochlorite is only around 15%. 

Sodium Hypochlorite is much more soluble than Calcium Hypochlorite, with its poor corrosiveness, it’s easier to use in your own house. Calcium Hypochlorite may produce sediment after dissolution, while Sodium Hypochlorite doesn’t. But do not contact with Sodium Hypochlorite, it may burn your skin. And keep them away from your children and valuables. Do not mix them with any other chemicals. 

V. Conclusion

As we can see, the differences between Calcium Hypochlorite and Sodium Hypochlorite are as below:

Calcium Hypochlorite is more suitable for scenarios requiring high stability, long-term disinfection, or large-scale water treatment (e.g. swimming pools, agriculture). 

Sodium Hypochlorite suits daily household disinfection and convenience requirements (e.g. kitchen, bathroom).