Preservative Tips Euxyl k 903 & Optiphen bsb-n

Formulating

Preservative Tips Euxyl k 903 & Optiphen bsb-n

Posted by ozgirl on August 8, 2023 at 7:32 pm

Sorry in advance for another preservative question.

Currently we are using a phenoxyethanol based preservative in our surfactant based rinse off products but recently we have been getting a lot of customer push back regarding the use of Phenoxyethanol.

I have been asked to look into alternatives and the current market seems
to have no issue with benzyl alcohol. This is for a “natural” product
line so parabens, isothiazolinones and formaldehyde donors are also not
acceptable.

I am not sure where the push against phenoxyethanol is coming from as it is actually rated lower than benzyl alcohol on the EWG database and allowed in their EWG certified products. (Note - I do not think that EWG is a good database I was just looking in places our customers might go for information). Some of the other consumer apps I have seen rate benzyl alcohol a low risk even though it is an allergen 🙄.

I have come across Euxyl k 903 preservative (INCI: Benzyl Alcohol (and) Benzoic Acid (and) Dehydroacetic Acid (and) Tocopherol) and Optiphen bsb-n preservative (INCI: Benzyl Alcohol (and) Benzoic Acid (and) Sorbic Acid (and) Glycerin) which might be ok but look to be a little weak against gram negative bacteria.

We currently use a chelating agent (GLDA) and the pH is less than 6 (usually 5.5).

Has anyone used either of these preservatives successfully in surfactant products and have you needed to add any preservative boosters to boost performance? Any other issues? Best pH?

We will definitely do preservative efficacy tests and stability trials but was just hoping for some tips.

Any answers to my questions is appreciated (also feel free to vent about customers dictating which ingredients you use) .😊

ozgirl replied 9 months ago 4 Members · 8 Replies
8 Replies

PhilGeis

Member
August 9, 2023 at 6:02 am

Include Benzoate in any system - tho not enough on it’s own - its pKa is effectively lowered by typical shampoo surfacatnts. Not aware that tossing in other organic acids is that helpful but prob can’t hurt. Neither system is that great vs Gram negatives - so you might run challlenge testing diluted (50%, 70%) to get a feel for manufacturing/consumer risk.

Also take a look at preservative system in products P&G recently marketed with EWG (gack!).
- ozgirl
  
  Member
  August 9, 2023 at 6:23 pm
  
  Thanks Phil.
  
  Could you clarify if you mean to add additional sodium benzoate to the above preservatives or just look for preservative systems that include benzoic acid/sodium benzoate?
  
  Thanks for the tip about the dilution.
  
  I will have a look at the EWG verified products for more preservative ideas.
Abdullah

Member
August 9, 2023 at 8:44 pm

If you use benzyl alcohol+ sodium benzoate or phenethyl alcohol+ sodium benzoate it will be cheaper and more effective and you will be more in control.
- ozgirl
  
  Member
  August 9, 2023 at 11:01 pm
  
  Good idea.
  
  I haven’t worked with phenethyl alcohol before? What concentration of Phenethyl alcohol is recommended?
  
  Have you tried a combination of Benzyl Alcohol, Phenethyl Alcohol and Sodium Benzoate?
Trytryagain

Member
August 9, 2023 at 10:11 pm

I have noticed Phenylpropanol (70%) and ethylhexylglycerin (30%) used in some “clean” cleansers lately. I’m sure the ingredient terrorists will eventually have a problem with this too, and will ban all ingredients containing “eth”. EWG likes Phenylpropanol for now, it’s a “1” *eyeroll*

Big retailers like Sephora are now listing phenoxyethanol as a restricted (not entirely banned but the damage is done) ingredient for their “clean at sephora” brands, and I think a lot of the blame for the fearmongering falls on these retailers. EWG too, of course. EWG gets the ball rolling, then the big retailers run with it.
- ozgirl
  
  Member
  August 9, 2023 at 11:03 pm
  
  I will check it out.
  
  I really hate giving up my phenoxyethanol but unfortunately market pressures dictate what sells.
PhilGeis

Member
August 10, 2023 at 6:04 am
No! EWG Verified is BS! P&G’s products that used this in marketing are worth a look.

Benzoate is a good addition in shampoos - and benzyl alcohol/benzoate/chelator a good combination. But test it.
- This reply was modified 9 months, 1 week ago by PhilGeis.
- ozgirl
  
  Member
  August 14, 2023 at 5:51 pm
  
  Thanks Phil. I agree that the EWG verification is BS. Along with most of the other verification programs.
  
  I will definitely test any preservative system we end up going with. I am just trying to knock out any that are clearly insufficient before we go to trials.