Article by: Perry Romanowski

There are a wide variety of water types that you can use when formulating cosmetics.  Distilled, deionized, purified or tap water are all options for cosmetic formulators.  Here is the difference between all of them.cosmetic water

Tap water – When you get the water right from the drinking fountain or city water supply, it’s filled with a small amount of metal and mineral ions.  Often this will not have any effect on your cosmetic formula but it can especially if you are using any soap based ingredient.  Since you can’t control the level of ions in a formula it’s best to formulate with something that is a little better purified than tap water.

Distilled water – This is the oldest form of purifying water.  In this process water is boiled in a still.  The vapor is collected in a condenser and cooled to reform the water.  Theoretically, it removes all traces of contaminants except those that boil at a temperature lower than water such as some alcohols.  It also will absorb Carbon Dioxide from the air so the pH will typically be lower (pH 4.5 – 5.0).

Deionized water – This is water in which the non-water related ions have been removed.  Tap water is usually filled with ions from the soil including sodium, calcium & magnesium plus metal ions from the pipes such as iron and copper.  It is deionized by sending it through an ion exchange column which is a tube that contains a resin which will selectively bind with ions in water.  Ionized water goes in and deionized water comes out.  This process doesn’t remove organic contaminants, viruses or bacteria.

Demineralized water – This water is sent through an ion exchange process.  It’s pretty much the same thing as deionized water.  There really is no difference when it comes to formulating cosmetics.

Ultra Pure water – When you want just pure H2O this is what you want.  The water is first demineralized then it is sent through an electrodeionization process.  This is great for electronics and pharmaceuticals.  It’s probably over-kill for cosmetics.

There you have it, all the different water you might use when making cosmetic formulas.  It’s important to note that whatever water you use if you are making a cosmetic the only proper way to list it is on the ingredient list is WATER.


  1. Khushbu Agarwal

    Hi Perry,
    Would there be any diffenrce in distilled water used in batteries vs cosmetics

    1. Perry Romanowski

      No, not really. At least not the water before it’s used.

  2. Tayyab

    Which level of ph water and TDS of water good for cosmetics creams,
    Im going use water which ph is 3 is it food?

    1. Perry Romanowski

      I do not know what you are asking. Normal pH 7 water is used to make cosmetics.

  3. Hakim

    can RO permeate be used in cosmetics and hydroalcoholic gels production?

    1. Perry Romanowski

      I don’t know what RP permeate is.

  4. Tonia

    Does distilled vs deionized or even filtered tap water affect the efficiency of a conditioner since it contains cationic ingredients like BTMS, polyquats etc?

    1. Perry Romanowski

      Probably not in a way you would notice.

  5. Mary

    Can water that goes through a purifier or filter be used. What do you think about boiled water used to formulate

  6. Janette

    I have started blending essential oils and some recipes call for distilled water, can demineralised water be used instead?

    1. Perry Romanowski

      It may or may not work. That depends on the type of ingredients you are mixing. It will probably work though.

  7. Deja

    Hi Perry,
    Which is better in formulating cosmetics deionized or distilled water?

    1. Perry Romanowski

      Either one will work. Typically, companies use deionized water because it is easier to get.

  8. Linda Johnson

    What is the correct label nomenclature for an ingredient list of a product containing water, “deionized water (aqua)” or’ water (aqua)’? Explain.

    1. Perry Romanowski

      The correct label is WATER. Or AQUA if you are outside the US. The reason is because this is the designated name for all forms of water in the INCI Dictionary which is the official listing for cosmetic ingredient names.

      1. Linda Johnson

        Thanks Perry for your response.
        Was it a particular year that manufacturers were required to replace “deionized water” on the ingredient list with Water (Aqua)?

        Thank you!

        1. Perry Romanowski

          It is industry standard practice to use the listing of ingredients as listed in the INCI Dictionary. I don’t know if “deionized water” was ever an approved name.

  9. Valerie

    I know a couple facilities that use RO water. Thoughts?

    1. Perry Romanowski

      I think it is pretty much the same as deionized water.

  10. Joshua

    Hello Perry, pls I would like to know if tap water is used for formulating would adding EDTA to the water forestall any unwanted interference from metal ions in the water? And what is the normal concentration to use for say a basic shampoo formula?

  11. Joshua

    Thanks Perry for the reply.
    I really appreciate it.

  12. Joshua

    Hi Perry,
    that’s a very nice article you put together there.
    However, I would like to know if the pH of the water has any effect on the viscosity of the final product in this case a shampoo; especially if distilled water is used as it has a pH about 4.5 – 5.

    1. Perry Romanowski

      The pH of the final product can have an effect on viscosity. Since the water is not buffered it will quickly take on the pH of the ingredients added to it so it’s unlikely that you would notice much difference just due to the starting water. But it could have a slight effect.

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