Question regards caustic soda
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They should say on them if there is anything else in there or if they are 100%.
Bear in mind that there are two things to consider - the ingredients in the bottle itself but then also the purity of the sodium hydroxide itself. So it might consist of 100% sodium hydroxide but the sodium hydroxide itself is 90% pure. This second figure is not likely to be on the bottle, but should be available from the manufacturer
Bear in mind that there are two things to consider - the ingredients in the bottle itself but then also the purity of the sodium hydroxide itself. So it might consist of 100% sodium hydroxide but the sodium hydroxide itself is 90% pure. This second figure is not likely to be on the bottle, but should be available from the manufacturer
According to this http://www.greenham.com/datasheets/662371.pdf its made with sulfuric acid, not suitable for soap. Caustic soda is such a broad term, I wouldn't buy anything with that label unless it says 100% sodium hydroxide.
You can get it on ebay http://www.ebay.co.uk/bhp/sodium-hydroxide
You can get it on ebay http://www.ebay.co.uk/bhp/sodium-hydroxide
I also found it on amazon.com.uk:
https://www.amazon.co.uk/s/ref=nb_s...d-keywords=sodium+hydroxide&sprefix=s,aps,732
https://www.amazon.co.uk/s/ref=nb_s...d-keywords=sodium+hydroxide&sprefix=s,aps,732
There is a product that is sulfuric acid (Knock Out Drain Cleaner, msds 662371.pdf) which is not remotely suitable for soap.
There is another product that is based on sodium hydroxide (Knockout Kitchen and Bathroom Cleaner, msds 509052.pdf). MSDS (material safety data sheets) do not necessarily tell you all the ingredients, but they can provide important clues. This particular product also appears to contain liquid sodium hypochlorite (aka chlorine bleach). Given that it contains bleach and water, this product is not going to work for soap either.
You have to look at the ingredients lists either on the bottle, or the ingredients list at the manufacturer's website, or the (partial) ingredients shown on the MSDS. If the product contains a mixture of sodium hydroxide and any other chemical, including water, the product is NOT going to work to make soap.
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As The Gent explained earlier, the ingredients list is one thing. There is the other issue of purity. Do not confuse the percentages of chemicals shown on an ingredients list with the purity of a specific chemical.
Here's an example -- Think of a glass of drinking water sitting on your desk. The water is 100% water right from the tap -- you haven't added any flavoring, or tea, or sugar, or anything else. The ingredients list for what's in your glass would correctly be 100% water. There's no question about that.
But think about water in a deeper sense. Drinking water, even if carefully purified, always contains trace amounts of calcium, magnesium, and other minerals. These impurities are chemicals naturally present in water that give water its characteristic taste. So that water in your glass, although it is 100% water, is not absolutely 100% chemically pure H2O.
The same is true for sodium hydroxide. The container of sodium hydroxide in my soaping cabinet contains no other ingredients intentionally added by the manufacturer, so the ingredients list contains just one chemical -- 100% sodium hydroxide -- with no other chemicals.
But my sodium hydroxide is not 100% chemically pure NaOH. It contains 95% pure NaOH and about 5% impurities. The 5% of impurities were not intentionally added; they are naturally there due to the water and carbon dioxide in the air that easily react with NaOH and due to the trace metals that come from the process used to manufacture the NaOH.
Sodium hydroxide that is not 100% pure can definitely be used to make soap. If the purity is quite low -- for example, some people report using sodium hydroxide with 85% purity -- a person might want to adjust the amount of sodium hydroxide weighed out to compensate for the low purity. If your sodium hydroxide is 98% pure, however, I'd not worry about making corrections.
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The name "caustic soda" is an accepted common name for sodium hydroxide, NaOH. Consumers in the US apparently don't use this name all that much, but it is often used in industry and, from what I can tell, it is also often used in other countries besides the US.
"Caustic soda" can be confused with the term "soda," however. "Soda" is an alternate term for soda ash (aka washing soda, sodium carbonate) which is not at all the same as caustic soda, sodium hydroxide.
So when in doubt, look at the ingredients list for clarification, because ingredients lists should use proper chemical names (in other words "sodium hydroxide" or "NaOH" rather than "caustic soda.")
There is another product that is based on sodium hydroxide (Knockout Kitchen and Bathroom Cleaner, msds 509052.pdf). MSDS (material safety data sheets) do not necessarily tell you all the ingredients, but they can provide important clues. This particular product also appears to contain liquid sodium hypochlorite (aka chlorine bleach). Given that it contains bleach and water, this product is not going to work for soap either.
You have to look at the ingredients lists either on the bottle, or the ingredients list at the manufacturer's website, or the (partial) ingredients shown on the MSDS. If the product contains a mixture of sodium hydroxide and any other chemical, including water, the product is NOT going to work to make soap.
***
As The Gent explained earlier, the ingredients list is one thing. There is the other issue of purity. Do not confuse the percentages of chemicals shown on an ingredients list with the purity of a specific chemical.
Here's an example -- Think of a glass of drinking water sitting on your desk. The water is 100% water right from the tap -- you haven't added any flavoring, or tea, or sugar, or anything else. The ingredients list for what's in your glass would correctly be 100% water. There's no question about that.
But think about water in a deeper sense. Drinking water, even if carefully purified, always contains trace amounts of calcium, magnesium, and other minerals. These impurities are chemicals naturally present in water that give water its characteristic taste. So that water in your glass, although it is 100% water, is not absolutely 100% chemically pure H2O.
The same is true for sodium hydroxide. The container of sodium hydroxide in my soaping cabinet contains no other ingredients intentionally added by the manufacturer, so the ingredients list contains just one chemical -- 100% sodium hydroxide -- with no other chemicals.
But my sodium hydroxide is not 100% chemically pure NaOH. It contains 95% pure NaOH and about 5% impurities. The 5% of impurities were not intentionally added; they are naturally there due to the water and carbon dioxide in the air that easily react with NaOH and due to the trace metals that come from the process used to manufacture the NaOH.
Sodium hydroxide that is not 100% pure can definitely be used to make soap. If the purity is quite low -- for example, some people report using sodium hydroxide with 85% purity -- a person might want to adjust the amount of sodium hydroxide weighed out to compensate for the low purity. If your sodium hydroxide is 98% pure, however, I'd not worry about making corrections.
***
The name "caustic soda" is an accepted common name for sodium hydroxide, NaOH. Consumers in the US apparently don't use this name all that much, but it is often used in industry and, from what I can tell, it is also often used in other countries besides the US.
"Caustic soda" can be confused with the term "soda," however. "Soda" is an alternate term for soda ash (aka washing soda, sodium carbonate) which is not at all the same as caustic soda, sodium hydroxide.
So when in doubt, look at the ingredients list for clarification, because ingredients lists should use proper chemical names (in other words "sodium hydroxide" or "NaOH" rather than "caustic soda.")
Last edited:
LilyJo
Well-Known Member
If you have been looking at Soap Kitchen then get the one they sell (or from a similar seller) - it is designed for soap making
Hi all thanks for your answer. I have been using caustic soda from wilko which has 98% caustic soda in it, i get it from JTF £ 0.79 per 500 g (£ 2.79 at wilko )seems alright and trace fine and no after affect. The other one is also from JTF £ 2.54 for 1 kg *Barrettine knockout caustic soda but as it said only caustic soda on it i thought it would be the same, looks like i will be using that for cleaning the toilet with
The caustic soda in Norway, with the brand name Solid, is sodium hydroxide only. But the data sheet says it is 90-100% sodium hydroxide. So the rest must be impurities or water (lye will soak up water from the air), since the ingredients are sodium hydroxide with no additives. If you can find data sheets on the products you have available where you are, it should tell what exactly is in there, and dangers, how it should be handled etc, etc. But they must write the content.
It doesn't necesserily have to be something else added even if the percentage is under 100%. I don't know how it gets under 100, but I guess someone knows.
And this caustic soda we have here, sold at every grocery store (at the bottom shelves so chilren can reach it!), is the one recommended by Norwegian soap makers (I did research on what and where to buy). And I guess there will be a caustic soda in other countries as well, that has nothing else than lye in it. And if you can find the brand name Stabil, it should be safe to use. I don't know if it's a Norwegian only or an international brand.
It doesn't necesserily have to be something else added even if the percentage is under 100%. I don't know how it gets under 100, but I guess someone knows.
And this caustic soda we have here, sold at every grocery store (at the bottom shelves so chilren can reach it!), is the one recommended by Norwegian soap makers (I did research on what and where to buy). And I guess there will be a caustic soda in other countries as well, that has nothing else than lye in it. And if you can find the brand name Stabil, it should be safe to use. I don't know if it's a Norwegian only or an international brand.
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