Home Cosmetic Science Talk Formulating Advanced Questions Can 5% propanediol used with Euxyl PE 9010 be an irritant?

  • Can 5% propanediol used with Euxyl PE 9010 be an irritant?

    Posted by grapefruit22 on May 3, 2022 at 1:10 pm

    Hi,
    Can propanediol at 5% with 1% Euxyl PE 9010 used in a face toner cause a skin irritation? I have no problems with propanediol when used alone. I also use Euxyl pe 9010 very often without any issues, so I wonder if maybe this combination is not good, especially in a quick-absorbing water-based product. I know that at least according to marketing materials, propanediol should not cause any irritation, even at higher concentration. Do you use propanediol at this concentration? Any issues? Can the amount of Euxyl be reduced when used with propanediol?

    JOJO91343 replied 1 year, 9 months ago 4 Members · 6 Replies
  • 6 Replies
  • PhilGeis

    Member
    May 3, 2022 at 1:35 pm

    Diols generally can cause irritation - and some users experience this in context of deodorants.  Generally takes a fairly high level and is transient.  Disappears with continued use.
    As grapefruit observed, very doubtful in apparent context of your question.

  • grapefruit22

    Member
    May 3, 2022 at 1:51 pm

    Maybe the problem is with Euxyl pe 9010 at 1%? It’s rarely used in face toners. The other ingredients are mainly sodium hyaluronate in a small amount, chlorphenesin and some extracts. Could pH make a difference? It’s around 4.5, so it’s not low, but I have no idea what might be causing these problems. It’s not a big irritation, slight redness and it disappears after a while.

  • markbroussard

    Member
    May 3, 2022 at 2:26 pm

    @grapefruit22

    You’ll have to do a knock-out experiment.  Prep one sample w/o Propanediol and one sample w/o PE9010 and a third sample with neither Propanediol nor PE9010.  That will help you understand if the irritation is from one the Propanediol, PE9010 or one of the extracts.  If the sample w/o Propanediol and PE9010 is still irritating, then you know one of the extracts is the most likely culprit and you can do a knock-out eliminating each of the extracts to determine which one is causing the problem.

  • grapefruit22

    Member
    May 6, 2022 at 3:22 pm

    @PhilGeis, @MarkBroussard, thank you for your input. I did a knock-out experiment. Triple dose extracts - no irritation. Euxyl Pe 9010 - I made a 1% solution, after applying no irritation. In short intervals, I applied it two more times, after the second very minimal signs of irritation.
    Propanediol - I started with 20%, I thought that if there are no problems at this concentration, then it will mean that the problem is for sure not with this ingredient. A slight redness appeared at this concentration. What’s more, after a short time, something like an acne spot appeared on the face. The next day I tried to lower the concentrations and the situation was similar (again - acne spot). At 2%, no problems.
    I don’t know if this experiment was really well done. I was doing it for a few days, but maybe after the first time the irritation didn’t completely disappear and it had some impact.

  • markbroussard

    Member
    May 6, 2022 at 6:30 pm

    @grapefruit22

    I would suggest you run a sample with 5% propanediol if that is your target load.  Running samples at a percentage different from what you intend to use in the product doesn’t tell you precisely what you are looking for.

  • JOJO91343

    Member
    May 15, 2022 at 3:15 am

    May be you used Sodium Hydroxide or Potassium Hydroxide to adjust pH upward to 4.5. You may check that, also

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