Liquid Soap Preservation : Sodium Beozoate

[Lankan]

I'm was suggested to use Sodium Benzoate as the preservative in the liquid soaps.

However, Wikipedia says Sodium Benzoate is effective upto pH 4.5 only. When I asked the chemist who suggested it, He said when molds grow they form a slightly acidic envirnment and the Sodium benzoate will become effective in it, effectively killing the mold.

Anyone tried using sodium benzoate as preservative in their soaps, I saw it in a commercially sold SLAS based handwash.

I would like to use it especially because it is a food grade preservative and easy to handle.

 

[lsg]

If your liquid soap has a pH above 6, Sodium Benzoate may not work.

"Sodium Benzoate is effective in products with a pH of 6.0 or below."

https://voyageursoapandcandleusa.com/products/sodium-benzoate-preservative

 

[DeeAnna]

They review sodium benzoate here: http://makingskincare.com/preservatives/

My reaction? There are far too many "ifs" and "maybes" in the chemist's advice for me to feel comfortable with their recommendation.

 

[Arimara]

If your liquid soap has a pH above 6, Sodium Benzoate may not work.

"Sodium Benzoate is effective in products with a pH of 6.0 or below."

https://voyageursoapandcandleusa.com/products/sodium-benzoate-preservative

Shouldn't all soaps be above pH7? How is it different for liquid soap, unless it's the dilution that makes it weaker?

 

[DeeAnna]

Diluted KOH liquid soap also has an alkaline pH about the same as NaOH bar soap.

I believe you may be misinterpreting lsg's sentence. Try putting the word "Since" in place of "If" and it might read better to you.

 

[Zany_in_CO]

You may be like me and not need any preservative at all. Here's an article that addresses both sides of the issue:

http://alaiynab.blogspot.com/2014/12/liquid-soap-faqs.html#more

 

[Deb Walker]

Is there any reason that colloidal copper citrate can't be used as a "preservative".
Use this as some of the dilution water.
I use it in my bar soap for a few reasons, including the antiwrinkle effects (strengthens collagen and reduces old lady dark spots). Since we have been using this people have been commenting that we look younger.
Copper is a very good antifungal etc

 

[Lankan]

thank you every one for the responses, I came across another preservative, Phenoxyethanol which according to Wiki is effective upto ph10. Any thoughts on this

 

[lsg]

Here is what Lotioncrafter says about Phenoxyethanol.
"Phenoxyethanol is a preservative used in cosmetics and personal care products. It is a biocide which is most active against Gram-negative bacteria. It is generally used in combination with other preservatives, in part because its activity is weak against yeast and mold."

 

[Lankan]

Here is what Lotioncrafter says about Phenoxyethanol.
"Phenoxyethanol is a preservative used in cosmetics and personal care products. It is a biocide which is most active against Gram-negative bacteria. It is generally used in combination with other preservatives, in part because its activity is weak against yeast and mold."

Can we use both Sodium Benzoate & Phenoxyethanol in combination.

 

[DeeAnna]

Please provide your reasons for thinking this combination might be effective. Since sodium benzoate is not recommended for use at high pH, what reputable sources of information have made you think this combination may work in the high pH of liquid soap?

 

[lsg]

Why not just use liquid Germall Plus, which is a broad spectrum preservative, effective against bacteria, yeast and fungus?

 

[Zany_in_CO]

Preservatives are designed for leave on skin care products and, as far as I know, there isn't one specifically formulated for liquid soap. Why not skip the preservative and see how it goes?

Fully saponified liquid soap doesn't require a preservative according to Catherine Failor who wrote "the Bible" on liquid soap. There are many LS-ers who are like me and don't use a preservative in their liquid soap. But we don't have any unsaponified fatty acids floating around, don't mess with lowering the pH or using additives that attract bugs.

There's good information on both sides of the issue here:

http://makingskincare.com/preservatives/

 

[Lankan]

I've been making CPLS for about an year. I dilute the paste in small batches and hadn't used any antioxidants or preservatives. the soap we use at home never gone bad. However, recently I came across two bottles I've gave away to my relatives, which had lost color and gone bad. Since then I'm trying to find an antioxidant and a preservative for my LS. I've looked at BHT as a antioxidant and once raised a thread on this forum also. However, the advise was not positive. So I'm still looking for a better alternative.

On the other hand, I'm not keen on using DMDMH which is a antimicrobial formaldehyde releasing preservative, which I don't want to use in my products. Apart from that the preservatives available locally are Sodium Benzoate & Phenoxyethanol. A chemist told me that when mold/fungies grow, they create an acidic environment around them, at which Sodium benzoate will become active. On the other hand Phenoxyethanol is effective against bacteria up to pH 10. This is the reason I'm trying see whether the combination of two can work.