Home Cosmetic Science Talk Formulating Preserving Clay Masks

  • Preserving Clay Masks

    Posted by dnyc2019 on December 15, 2018 at 4:56 pm

    Hi all, had a clay mask fail and go moldy, even after using Optiphen Plus. PH was 6, and it was added after cool down at room temperature, so it should have held up. I know clay is notoriously hard to preserve, so I want to get this right. Any thoughts on why this would go bad and what I can do to ensure it doesn’t happen again? Full ingredient list:  distilled water, unrefined shea butter, bentonite clay, kaolin clay, cetyl alcohol, castor oil, glycerin, citric acid, dead sea salt, charcoal, peppermint oil, tea tree oil, fragrance, and grapeseed oil. Thank you in advance!

    ChemistCradle replied 5 years, 8 months ago 8 Members · 14 Replies
  • 14 Replies
  • Doreen

    Member
    December 15, 2018 at 4:59 pm

    pH 6 is too high for Optiphen plus. The sorbic acid in Optiphen Plus is inactivated at a pH that high. And it’s the sorbic acid that is active against mold.
    Do you use clay that is sterilized (by radiation)? Remember, clay is dirt!

  • dnyc2019

    Member
    December 15, 2018 at 5:39 pm

    Thanks for your help! Ah I thought it could go up to a PH 6. Just started using Optiphen plus, so I see that’s where I made the mistake. Going to add a bit of citric acid. And yes, clay is sterilized.  

  • MarkBroussard

    Member
    December 15, 2018 at 6:08 pm

    Clay products are notoriously difficult to preserve.  I would recommend that you consider adding Tetrasodium Glutamate Diacetate (chelating agent), Phenethyl Alcohol and either p-Anisic Acid or Naticide (Parfum) to bolster your preservative system and bring your pH down to 5.0.

  • Bubbles

    Member
    December 17, 2018 at 3:12 pm

    Obviously I yield to your years of industry experience @MarkBroussard, but I read that chelating agents are overwhelmed and rendered ineffective in most clay based products. Does this effect vary depending on the variety of clay used? e.g kaolin v bentonite v rhassoul.

  • MarkBroussard

    Member
    December 17, 2018 at 3:40 pm

    I’ve never seen anything substantiating that chleators are rendered ineffective in clay products, but if you have some credible evidence of that, by all means post it up.  

  • Bubbles

    Member
    December 17, 2018 at 3:53 pm

    I believe I read it on this Forum at some point, I believe posited by @Belassi, I just joined the industry about 8 months ago so my specific cosmetic knowledge is limited. I found this article,

    https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/153620/ANDOTRA-THESIS-2014.pdf?sequence=1

    In the abstract it stated that in their test, 1% citric performed the best but when compared to their sample without citric acid, and factoring in the cost, it became an unfavorable option. Also, clays are mostly made of aluminous minerals.

  • ngarayeva001

    Member
    December 19, 2018 at 9:07 pm

    @Bubbles this is a discussion you are referring to https://chemistscorner.com/cosmeticsciencetalk/discussion/4817/raw-material-first-cosmetic-product-assurance-for-industry-novice-to-not-go-wrong-way

    If I understand it right, clay contain so much of metal ions that EDTA will be overwhelmed by it. Too much of EDTA would be required to bind all these ions.

  • Dirtnap1

    Member
    December 19, 2018 at 9:49 pm

    If you don’t mind the preservative to be a formaldehyde releaser, DMDM Hydantoin should work in your formulation. 

    Any way to make the formula anhydrous by chance? 

  • vjay

    Member
    December 21, 2018 at 11:38 am

    Need to add multiple preservatives for the clay mask like phenoxyethnaol, ethylhexyl glyceirn, if possible you can add parabens.

  • dnyc2019

    Member
    January 9, 2019 at 4:30 am

    Thank you all. Tried again with a ph of 4 and added .5% alcohol and 1% citric acid in addition to the Optiphen Plus. Within less than 24 hours Mask looked like this. Is it possible this reaction is something other than fungi? 

  • Doreen

    Member
    January 16, 2019 at 3:22 am

    Fungi usually need more time to grow, less than 24 hours is very quick. What happened in the last week?
    And what was the reason for adding the 0.5% alcohol?

  • ChemistCradle

    Member
    January 16, 2019 at 9:35 am

    I found Germall Plus very active even at 0,2% working with clay. Its upper limit is at 0,5%, so make a try. About chelating agents and clay: depending from clay specifications they can be completely useless because the clay itself acts as chelating or exchanger. It can depend from mineralogic composition, site, and even from preconditioning process before the market.

  • ChemistCradle

    Member
    January 16, 2019 at 9:38 am

    The white points could be Salt efflorescence. Try to isolate, and put in few drops of distillated water. If you have cristallization again, no fungi.

  • MarkBroussard

    Member
    January 16, 2019 at 8:19 pm

    Why don’t you just test it with either a microbial dipstick or send it to a lab for a plate test.

Log in to reply.

Chemists Corner