Dear Soap Coach: “ I currently make soy candles and bar soap (both cold process & hot process). I have made liquid soap for my own use. I joined a liquid soap group & there is such controversy about using preservatives in liquid soap both for and against. In your liquid soapmaking class, do you teach your students to use a presevative? ” - Sonya Dixon, owner of Dixon Candle and Bath, LLC
Thanks Sonya for allowing me to post your question. Making liquid soaps can be fun but also challenging. Part of the challenge is wondering if you need to preserve your liquid soap when you don’t have to add preservatives to bar soaps.
During the liquid soapmaking process you don’t have to add a preservative. You have a soap paste that is ready to be diluted in water. Once however you are ready to dilute the soap paste in water or any other liquid you will need to add a preservative. Why?
Now your liquid soap is a majority of water. Water is needed to sustain life and unfortunately it sustains the life of the dreaded nasty guys such as bacteria, mold and fungus too. When making quality personal care products you must keep the end consumer in mind. Yes, we want to make natural skin care products. But when it comes to consumer safety your natural skin care product my be 98% natural instead of 100% with the addition of a preservative. In reality your 98% natural skin care product will be 98% better than the stuff sold on most supermarket shelves.
You also don’t know the condition of the persons skin when they are using their product. Do they have a paper cut on their finger or a minor abrasion on their leg. They use your unpreserved liquid soap and yes it is a rinse off product but it only takes a millisecond for an infection to take place and for that bacteria to breed and spread throughout a persons body.
So, how do you preserve your liquid soaps? There are some alternatives that you can keep in mind when preserving your liquid soaps. I bet you thought I would say adding vitamin E aka tocopherols or rosemary extract. Nope, those ingredients are great antioxidants and will help any free standing unsaponified oils in slowing down rancidity but it won’t preserve. Oh yea, essential oils right? Yea, they can but the level you would need to use would be unsafe and toxic for human use.
A couple of options do come to mind:
- Choose a Non Paraben Preservative – There are preservatives that has full spectrum preserving properties. Be sure to read the MSDS sheets from the supplier about the preservative and it’s effectiveness. You will need to know at what ratio can you preserve a product and also important factors such as heat sensitivity may play a role in when to add the preservative. Examples of non paraben based preservatives are Optiphen and Liquid Germall Plus.
- Try a Natural Preservative: Yes, I did say natural. Though I have not tried this one myself you can purchase a natural preservative from Lotion Crafters called NeoDefend. Please consult the supplier on how to properly use this ingredient. It is acceptable for use by Ecocert as a preservative in organic cosmetics so this might be a good choice to try for a “natural” preservative.
- Test Your Product: Send your preserved or even your un-preserved liquid soap to be microbial tested. This way you will know if when you are preserving your product that you are preserving at a level that is sufficient. Please keep in mind that no product will be 100% bacteria free but there are level of microbials that become unsafe.
Please remember that your ultimate goal as a natural skin care manufacturer is to produce a quality product that is SAFE. We can’t control what the end user will do with the product once they get home no matter how many warnings are listed on the label. We have seen this time and time again especially in the supplements industry where people don’t take the proper dosage that is outlined on the bottle for safe use and then end up very sick or even worse dead. The result the product is taken off the shelves. Always remember to produce a SAFE product and do what is necessary to keep it safe even in the hands of the consumer.
For those who make natural skin care with preservatives especially in regards to liquid soap, what preserving system do you use? Please share below.