Caustic soda flakes

Where to Buy Caustic Soda in the UK

Caustic soda, or sodium hydroxide, is an alkali that is used for a variety of purposes. It is commonly used in the manufacture of paper products, soap, water treatment, textiles, and more.

In addition to its commercial uses, caustic soda can also be used for a variety of household cleaning tasks. This one simple product can help tackle blocked drains, clogged waste pipes, and can sanitise bins to name just a few.

Where to Buy Caustic Soda in the UK

Unfortunately, because it can be also used in the manufacture of illegal drugs and can be dangerous when used incorrectly, caustic soda is difficult to buy in large quantities in the UK. However, it is possible to find small household packets both online and in stores.

As a result of this restriction, it is often easier to find cleaning chemicals that contain caustic soda rather than caustic soda itself.

In Shops and Supermarkets

The semi-restricted nature of caustic soda means that it might not be available in every shop or supermarket in your area. However, it is available in some hobby, DIY, or hardware stores, such as B&Q or Homebase.

It is likely that you could find a household cleaning chemical that contains caustic soda in most supermarkets, such as:

  • Asda
  • Tesco
  • Sainsburys
  • Morrisons
  • Waitrose
  • Marks & Spencer
  • Co-Op
  • Aldi
  • Lidl

Other stores that sell cleaning products will likely also have cleaning chemicals that contain caustic soda available:

  • Wilko
  • The Range
  • Home Bargains
  • B&M Bargains


Alternatives to Caustic Soda

Whilst these products cannot be used as a direct replacement for caustic soda, they can be used to tackle the same cleaning tasks that you would use caustic soda for.

Bicarbonate of soda and distilled white vinegar can be used to tackle clogged drains, sanitise bins, and clean toilets, even if you have a septic tank.

1. Distilled White Vinegar 5L

Jocker Woods White Vinegar for Cleaning, Pickling, Marinations & Cooking - Distilled White Vinegar - 5 Litre Bottle - Produced in The UK (1Pack)

Distilled white vinegar from Jocker Woods is readily available on Amazon in a handy 5 litre bottle which is ideal for homes looking to use a more natural product to tackle cleaning tasks in the place of harsher ones, like caustic soda.

This 5-litre bottle is very reasonably priced, and can be used in a wealth of recipes on top of simply cleaning.


2. Bicarbonate of Soda 1kg

Grow Chem Baking Soda, Sodium Bicarbonate (1KG Bucket) UK MADE Pure Baking Soda for Cleaning, Baking, Bath Bombs, Odours and Teeth

Bicarbonate of soda is a household staple. On its own, it gives a stunning rise to baked goods. When used in combination with water or distilled white vinegar, it can tackle a variety of household cleaning tasks with ease.

As opposed to other cleaning chemicals, bicarbonate of soda can deodorise without leaving behind a strong chemical scent.


Caustic Soda FAQs

Is caustic soda harmful to humans?

Caustic soda is potentially dangerous when used in large quantities, for long periods of time or without taking adequate precautions.

The level of harm that caustic soda can cause will depend on the amount, duration of contact, and the activity that was being undertaken. It can burn the skin, eyes, digestive system, and lungs.

Repeated skin contact can lead to skin complaints such as dermatitis.

Is caustic soda the same as bicarbonate of soda?

The two chemicals are not the same. Caustic soda is sodium hydroxide, and bicarbonate of soda is sodium bicarbonate.

Caustic soda is a corrosive substance that is alkali in nature that can cause chemical burns. As a result, caustic soda is mainly used as a cleaning agent and in laboratories.

Bicarbonate of soda, on the other hand, can be used as an antacid, a water softener, in fire extinguishers, as a pesticide, as a natural cleaning agent, and, of course, in baking.

Is caustic soda good for killing weeds?

Whilst caustic soda can kill weeds, it isn’t to be recommended as you would likely require large quantities of caustic soda to cover the required area. Stick to commercial weed killers, or sprinkle the area with salt, and spray with a mixture of vinegar and washing up liquid.

Can you mix caustic soda with vinegar?

Mixing caustic soda with vinegar or any other chemical whatsoever is not recommended as it can cause a violent chemical reaction.

This is certainly the case with vinegar. The reaction could be aggressive, causing damage or releasing harmful gases.


Uses of Caustic Soda


There are a variety of uses for caustic soda at home. Before tackling any task with caustic soda, make sure that you take adequate precautions to keep yourself and others safe.

A popular task for caustic soda is unblocking drains or pipes. Clogged drains are often caused by fats and grease. When caustic soda meets grease, it turns it into soap, which can be easily dissolved in water and simply washed away.


Outside of the home, caustic soda can be used for a variety of purposes. One common use is in the production of paper. The caustic soda is mixed with additional chemicals to break down wood to create pulp. Later in the process, caustic soda is also used to bleach the brown pulp to create white paper.

In some countries, caustic soda is also used as part of the food preparation process for some dishes, and can be used as a powerful degreaser on glass or stainless-steel cookware.


Using Caustic Soda Safely

The characteristics of caustic soda that make it good at cleaning are unfortunately the same ones that make it potentially dangerous. Caustic soda gets to work breaking down materials very quickly, which means that if it is in contact with skin, it can result in chemical burns incredibly quickly.

As a result, anyone handling caustic soda should always take adequate precautions like wearing rubber gloves, protecting the eyes, and covering up with safety clothing.