Toner pH 3.6 - preservative choice

Formulating

Toner pH 3.6 - preservative choice

Posted by ost85 on January 28, 2025 at 1:36 pm

Hello all,

I would like to use Verstatil® TBG MB (Triethyl Citrate, Glyceryl Caprylate, Benzoic Acid) solubilised to preserve a toner with a pH of 3.6. The paperwork says this preservative is for pH 4-6. My guess is that the benzoic acid become too much in a free state in low pH and can become too irritanting or precipitate.

However, then looking at a different manufacturer- SENSICARE C 2090 (Triethyl Citrate, Caprylyl Glycol, Benzoic Acid) their TDS says “the product is stable throughout a broad range of pH (from 2 to 12) .”

These are clearly different ingredients, but both have benzoic acid. So I wonder why sensicare is stable at as low as 2pH.

I cannot get Sensicare, and I can only get Verstatile. Is there anything I missed, because at the moment I think as long as the acid doesn’t precipitate I should be fine using it at 3.6. My other concern then is the irritation potential.

I would greatly appreciate any advice on Verstatil (Triethyl Citrate, Glyceryl Caprylate, Benzoic Acid) in 3.6 pH.

Thank you.

ost85 replied 8 months, 2 weeks ago 4 Members · 8 Replies
8 Replies

PhilGeis

Member
January 29, 2025 at 8:28 am

Neither is that great - Verastatil the the weakest - its pH range is prob driven by concerns for pH driven hydrolysis of its fairly-useless ester.

the 2-12 is absolute BS and should eliminate your consideration of that supplier.
- ost85
  
  Member
  January 29, 2025 at 1:52 pm
  
  Thanks, that wide pH range did seem very suspicious.
  
  The other two I have are:
  
  1. sodium benzoate + potassium sorbate, which I like generally, but they too seem not ideal for 3.6pH.
  
  2. phenoxyethanol + ethylhexylglycerin which is my fallback option.
  
  Do you have any suggestions for any others I should consider?
PhilGeis

Member
January 29, 2025 at 2:05 pm

I know some have found sorbic/benzoate good but it’s generally weak vs Gram negatives. Phenoxy+ is good v Gram negatives but weak vs Gram + and fungi. Ypu best off with a combination of the 2 - esp. benzoate and phenoxy+
- ost85
  
  Member
  January 30, 2025 at 4:14 am
  
  Thank you, much appreciated.
- Bluebird
  
  Member
  February 17, 2025 at 3:03 am
  
  How about Sodium benzoate + 1,2 hexanediol then, for low pH (ex, 4-5)?
  - ost85
    
    Member
    February 18, 2025 at 10:40 am
    
    Thanks for the suggestion. Unfortunately I don’t have access to 1,2 hexanediol to try it out.
Abdullah

Member
February 17, 2025 at 3:48 am

Sodium benzoate doesn’t have problem with low pH. Glyceryl Caprylate have.
- ost85
  
  Member
  February 18, 2025 at 10:32 am
  
  Thanks, seems like I was focusing on the wrong thing.