[Chemist79]

The pH needs to be less than 5.5 in the finished formula for SB & PS to effectively preserve. However adding them at a higher pH is fine as long as the finished formula is adjusted to <5.5

[Chemist79]

Try Laureth-4

[Chemist79]

Thanks @Bobzchemist I’ll give it a try

[Chemist79]

Yes I have seen this before, try finishing it with an excess of Stearic and neutralise it further when cooler

[Chemist79]

And I thought the EU was a minefield with the new BPR!!!!

[Chemist79]

Maybe it’s the anionic surfactant kicking the cationic CETAC and polyQuat out of the formula. Or could be the 2% high oil loading and insufficient surfactant to solubilise. Try making 2 samples, 1 without the cationic and one without fragrance and oils and see if it still splits

[Chemist79]

Well it is used to preserve Sprite, Fanta and Pepsi Max (E211) so that’s safe enough for me

[Chemist79]

Hi Gustavo, did you have any luck with this project? I would be interested in your findings, thanks.

[Chemist79]

I hate the internet scare mongerers too often they are journalists or bloggers basing their “expert” opinion on bad science and internet research. Until there is some real scientific data to suggest they are harmful to human health and they are prohibited by the EU cosmectic regulation I would be happy to use any of the dirty dozen (except coal tar, phthalates and the banned parabens obviously). I am surprised to see the thiazolinones didn’t make the dirty dozen yet mineral oil, the primary ingredient in most baby oils, did.

[Chemist79]

CHDG can be degraded by UV light so not to be used in a clear colourless pack. PHMB has a bad rep. BAC & DDAC are good but the cationic nature can make formulating expensive. Personally I always found Triclosan pretty useless for cosmetic purposes the kill is too slow. Glycolic acids and salicylates would be my personal choice.

[Chemist79]

I have always found ZP at 1% active material the best and most cost effective route. The trick is keeping it in suspension though without using expensive Carbomer type technology. Hot mix type ingredients Glycol distearate and cocamide mea work best, the good old Head & Shoulders route.

[Chemist79]

Lactic Acid is used a lot in Europe as an effective antibacterial agent in hand washes. You need to use a good amount 2 - 3% and pH of the final product is absolutely key. If formulated correctly it is possible to achieve a 5 log reduction versus the en1276 standard. I wouldn’t recommend essential oils they would need to be used in huge amounts to get any kind of proven antibacterial activity in your final product. That is the product itself showing some real antibacterial activity at realistic contact times and not just being based on historical data produced on pure oils at contact times of 5 minutes plus. It would almost certainly require you to list allergens on pack too.

My advise would be to stick with the Lactic Acid and complement it with another FDA approved biocide. I only know about the EU so not sure if it is included in the FDA but Salicylic Acid complements it well. You will need to use a solvent to get Salicylic into solution something like Propylene Glycol.

[Chemist79]

Not sure which region you are in but from an EU perspective it looks like either biocidal or medicinal labelling rather than a cosmetic.