Home Cosmetic Science Talk Formulating Does this need a preservative?

  • Does this need a preservative?

    Posted by cosmetic_chemist on April 6, 2022 at 3:59 pm

    Hi Everyone, 

    I am currently working on a few gym bag sprays/deodorizing room sprays and am unsure if I need a preservative. 

    Water - qs
    Alcohol - 40% (Another type would have 10%)
    Botanical extract blend - 0.01
    Fragrance - qs

    Does alcohol negate the need for a preservative? At what concentration of alcohol can I skip the preservative? Please let me know what you think!

    PhilGeis replied 1 year, 11 months ago 2 Members · 3 Replies
  • 3 Replies
  • PhilGeis

    Member
    April 6, 2022 at 4:48 pm

    20% is usually cited as an effective preservative level but alcohol per se does not justify skipping content testing unless you’ve appropriately qualified ingredients (including alcohol itself) and process.

  • cosmetic_chemist

    Member
    April 6, 2022 at 5:58 pm

    Thank you @PhilGeis for your response! 

    By content testing do you mean micro testing? Would there be a problem if I do add a preservative, Phenoxyethanol for example, to it even with 40% alcohol?

  • PhilGeis

    Member
    April 7, 2022 at 1:52 am

    Right - testing for viable microbes in the product to spec.  No problem that i know with added phenoxy but added cost.

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