Preservatives that are compatible with cationic conditioning agents

TaurielTauriel Member
edited January 2019 in Formulating
Organic acid compatibility with cationic agents

I'm using benzostat(caprylhydroxamic acid) as the preservative in a conditioner formula that uses btms and brassicamidopropyl dimethylamine as the cationic agents. Are they compatible?


  • Hello there all, 

    This is my first discussion as I am rather new here; I must say I do appreciate the helpful insight I have found here on chemistscorner. 
    I am new at formulating and I read on the Chemistscorner blog that some preservatives, mainly organic acid, are incompatible with cationic agents. Should I be concerned if I'm using Benzostat? What would be a compatible preservative? This will be my first conditioner recipe and I have only worked with benzostat so far in other emulsions.

    Any insight is gratefully appreciated!

  • chemicalmattchemicalmatt Member, Professional Chemist
    Compatibility here should not be an issue, but as with all preservatives relying on acid dissociation, maintain a pH < 4.5 and a level of organic acid at the maximum allowed and you should have good results. Factor that into the acid content you are using to co-emulsify with that tertiary amine (lactic or citric, I assume?)
  • Hello!
    Thank you for replying!
    Yes, citric acid. They recommend.14% of it to every 1%  B.dimethylamine, added to water phase. Initially, I'll be using the B. Dimethylamine at 3% (so citric acid at .42%). I thought I would check pH before adding preservative and then adjust accordingly(I have only just started learning about conditioners). Is it possible that the pH level of the finished conditioner ends up too low?

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