Home Cosmetic Science Talk Formulating Smell rancid

  • Smell rancid

    Posted by Mynkcosmo on November 3, 2020 at 6:02 am

    Hello so I started making some home made blushes and for some reason after a month or two of having them they started to smell rancid. I thought it was my wet ingredients but they all don’t smell. Then I thought it might be the oils I use and they also don’t smell. I have made two colors, a light and dark. I use the same base ingredients for both but obviously different mica and the dark color doesn’t smell. What can it be? Can anyone help me. 

    Mynkcosmo replied 3 years, 4 months ago 2 Members · 3 Replies
  • 3 Replies
  • pharma

    Member
    November 3, 2020 at 9:51 am
    A: Oil-air contact surface (that’s where rancidity happens fastest) is thousand times greater in a powder than an oil in a bottle. Shelf life drops considerably in a powder blush.
    B: Blushes often use iron oxides as primary pigment and it’s exactly the iron which accelerates the chemical reaction between oxygen an oil which has the latter turn rancid.
    -> Solutions would be: drop unsaturated oils, add antioxidants, use coated iron pigments (more expensive) or iron free pigments (which may not exist for your target colour).
  • Mynkcosmo

    Member
    November 16, 2020 at 1:40 am

    Okay. Thank you so much @Pharma. I will give that a try!!! 

  • Mynkcosmo

    Member
    November 16, 2020 at 1:59 am

    @Pharma so looking for a good Antioxidant to use with my cream to powder blush. Which one do you recommend?

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