Sodium hydroxide NaOH, or more commonly known as caustic soda, is a common chemical in industrial sectors. Being versatile, it has its uses in water and wastewater treatment plants, soap, detergent, cosmetics, and paper industries.

General Characteristics of Caustic Soda

Pure caustic soda is white, odorless crystalline solids at room temperature. One common way to produce NaOH is via electrolysis of salt (brine).  Caustic soda is highly alkaline in nature and readily soluble in water.

Caustic Soda’s Uses in Water and Waste Water Treatment Systems

1) As a pH adjuster

Being alkaline in nature, highly soluble in water and abundantly available makes caustic soda an ideal candidate as a pH adjuster. Most manufacturing lines produce water which is acidic in nature.

pH adjustment is the first step of chemical treatment of an IETS. This is important to ensure that wastewater is at certain pH (usually 6-9) to ensure that the subsequent step, coagulation works well. Also, heavy metals can precipitate and be segregated from later treatment stages.

2) Unclogging pipes and drains

Over time, fats and grease will accumulate in your pipes and drains, causing flow blockage and eventually overflowing. Upon contact with water, caustic soda solids generate a strong alkaline solution, which will react with these organic matters that can be washed away easily later.

3) Preventing scale buildup and corrosion in a boiler.

Caustic soda is the choice of chemical to use when it comes to preventing corrosion and scale build-up in a boiler. It maintains a pH value of more than 10. Such an alkaline environment inside a boiler helps to create an oxide corrosion coating. Being an oxygen scavenger also prevents further scale buildup. Also, caustic soda does not generate carbon dioxide which may form carbonic acid.

4) Adjusting pH of water supply

If water is acidic, you can use caustic soda to raise the pH of water to near neutral. Caustic soda is a good choice because it does not add calcium ions into water and causes further water hardness problem.

Caustic Soda’s Uses in Other Industries

1) Raw materials to make soaps

Caustic soda is involved in the saponification process, i.e. oils are converted to soap and glycerols, which are then washed away by water. Besides that, caustic soda maintains the pH of soap to ensure soap is safe to use on your skin or fabric.

2) Paper-making and recycling industries

Caustic soda breaks down the lignin bonds which bind wood’s cellulose fibers together. In bleaching step, for maximum efficiency, a bleaching chemical (for example, Hypochlorite) is often used together with caustic soda. In paper recycling industry, caustic soda separates ink from paper fibers.

3) Food industries

Caustic soda has many uses in different food industries. It can act as a preservative, pH adjuster, taste enhancer, leavening agent, curing agent and food peeling agent.


We supply caustic soda in flake form or liquid form, and its concentration can be adjusted to your requirement.

We are your choice caustic soda supplier in Malaysia. We supply caustic soda to various industries for various uses.

Please contact us for your enquiries on caustic soda.

Packing in flake form
Packing in liquid form