Neither Castor oil nor Finsolv will blend ingredients

I am trying to mix D-Limonene and Cola Quat into a stable mixture. In order for them to blend I have tried cold pressed and cold processed Castor oil, as well as Finsolv TN-O, but after just a few minutes all the ingredients seem to separate from each other.
Is it the amount of castor oil or Finsolv I use that is the issue?
So far I have been trying it with 1:1:1 (so, the same amount of each of the above ingredients). I use a simple kitchen mixer to first whip up the castor oil, then while the mixer is running I slowly pour in the D -Limonene and then finally I slowly add the Cola Quat. It mixes great...then a few minutes all separates. Please kindly help.


  •  That much d-limonene will be really, really bad for your skin. Why are you trying to do this?
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • You do not define the grade of ColaQuat that you are using.

    However, from what I gather both the PDQ and the SME grades comprise aqueous solutions. I suspect other types are similar. This being so, that is the reason the products fail to mix with an oil base.

    What is the intended end use of this product? As Bob says, that level of limonene is really bad for the skin - and would not be permitted in a cosmetic product in Europe, at least.
  • Hello Bob and John,

    Thank you for your replies.

    The formulation is not for cosmetical purposes but a household product (a spray). I cannot give many more details about it at the moment unfortunately, but it is definitely not intended to be applied to the skin.

    The Cola Quat has the following concentration:
    HET-CAM @ 1.5%, scored 10 (slight eye irritation). Zero skin.

    I was not aware that D-Limonene is dangerous. I thought it would have the same level of danger as essential oils (ie. very low risk).

    As my formulation will be a spray, according to my research Cola Quat is harmless if vaporized/atomized. However, now I am concerned that D-Limonene may be harmful if traces of the spray are inhaled. 
    I have been breathing in fairly large amounts of pure D-Limonene either when sprayed or even when working with it, for close to 14 months now (due to my various experiments). Should I be concerned?

    Best regards


  • edited April 2017
    My main concern with your query was the problem with obtaining a homogeneous mixture - which you will never achieve with the mix that you are using.
  • Equal parts of your three ingredients seems a gross excess of limonene in a product of the type you are formulating. The odour will be overpoweringly strong.

    Another thing - have you considered the long term effects on surfaces by spraying relatively high quantities of oils (be that castor oil or Finsolv) or of cationic detergents (the quat) on to surfaces (even if they are wiped away afterwards).

    I also see problems in being able to successfully spray a high viscosity material like castor oil.
  • Here at Beaumont Products, we work with d-limonene in many of our products. D-limonene itself is a reasonably strong solvent, and should be treated with the same amount of caution as Acetone is, especially when it comes to PPE.

    But the real harm comes in if it is allowed to  oxidize (we store and process ours under nitrogen blankets at all times to prevent this). Oxidized d-limonene is a very nasty allergen/sensitizer, and can cause very bad reactions on skin. 

    I can't say whether or not spray will be harmful - read your SDS and do a Google search to find out for yourself.

    D-limonene also has the ability to extract plasticizers from plastic blends (like the ones used for bottles), making it critical to run long-term stability tests on your packaging. Plastic without plasticizer is brittle - this is a very bad trait in a package that you want to stay intact.

    D-limonene isn't at all soluble in castor oil. If the castor oil is required in your formula, you're going to have to make an emulsion, and I can tell you from experience, making a stable emulsion with even 1% of d-limonene is a major pain in the butt. 30% or more will probably be impossible. It should be possible to solubilize that much, but you're going to have to get really creative with coupling agents.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • Thanks for that, Bob. Now I know why a vinyl record cleaner I made with D-Limonene in it separates after a few weeks.
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
  • #Belassi Dont know what level you need but .3% polysorbate 80 forms a stable emulsion with .3% D Limonene.
  • Thank you so very much again everyone for all this fantastic advice!! Superb!
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