[LuisJavier]

I’m really struggling to come up with a robust preservative system for the carbopol 940. I do not know if Euxyl PE 9010 will be enough and I do not want added glyceryl caprylate to possibly hydrolyse at pH 7. Are you comfortable making a carbopol 940 emulsion-face cream with pH 6 or do you think the purpose for using the carbopol is being defeated? With Sepimax Zen, it seems like I could use sodium benzoate or potassium sorbate in addition to the phenoxy.+EHG and have a well-preserved face-cream. What is your thought process on the carbomers and other acrylate polymers when thinking about preservatives and skin-feel? 

[LuisJavier]

I think I misunderstood your comment; I think you were referring to ‘more robust’ preservative systems as opposed to ones like Spectrastat OEL. 

[LuisJavier]

I’ve tested a batch of the carbopol 940 against the sepimax Zen and I think I agree with your sensation. I’ve not managed to get my hands on any other carbomer apart from Carbopol 940 as of yet - it doesn’t seem so easy without contacting large companies. I just looked at viscosity differences between Carbopol 940 and Ultrez 10. Seems like Ultrez 10 has about 5000 units more viscosity-increasing effect than Carbopol 940. Not only that, I discovered that there are apparently benzene residues in Carbopol 940. Strange. Ultrez 10 seems to use other solvents for production. In regards to the preservative system, I think the Euxyl PE 9010 seems quite robust to be honest. I don’t know what other kind of preservative system you’d recommend. I’m quite averse to using formaldehyde-releasers but I’m ok with parabens. Only problem with parabens is finding a supplier since parabens do seem to be undergoing a phase-out in the cosmetics industry.

[LuisJavier]

That’s a good point. I could agree that cigarette smoking seems to be far more harmful than tiny levels of dioxane.

[LuisJavier]

What is your favourite carbomer?

[LuisJavier]

I did not know that the average number of mutations needed for cancer to develop is 4.  I’m a bit puzzled by how I fell into that fallacy; I do not mean that the probability of getting cancer at each subsequent stage increases from the last, but that if a person is put into a situation where he/she adds a risk factor and maintains it as a routine, like smoking, then by the end of 20 years, it could be sargued that developing cancer is more likely for this person than for a person who only smoked 1 cigarette in their life (when you consider a large population demographic of course). 

[LuisJavier]

Thank you all for your comments. I did have in mind to test some of the physical properties of the powder so as to make somewhat sure that it is in fact niacinamide. 

[LuisJavier]

I didn’t know bananas contain radioactive potassium. Do you have any papers on this?

[LuisJavier]

Thank you Perry for your response. The issue of ethylene oxide impurity is the crux of the matter for me. I fully understand that on the whole, at accepted usage levels, phenoxyethanol is very safe in cosmetics, but I have a lingering thought: ‘For cancer, all it takes is possibly one mutation, and if EO is carcinogenic, and even if it is in a tiny percentage in a bottle of phenoxyethanol, then the risk for that mutation to occur only increases as application of this preservative is maintained.

I admit, I do have to consider that the impurity percentage is further minimised when you take into account the percentage of the preservative in the entire cosmetic product, so yes, this preservative really isn’t the worst thing out there.

In regards to my concern in the third sentence, is this concern one of exaggeration? I’m not certain but I remember reading that even car exhaust contains small amounts of carcinogens too, as well as a tiny percentage of asbestos fibres that make up the air we breathe here in the UK. Finally, I’m open to a response to the concern I’ve mentioned in regards sustained exposure to tiny levels of EO, and I will take up your advice and just use phenoxyethanol, probably in combination with sodium benzoate (and potassium sorbate?). Many thanks again. 

[LuisJavier]

I see. So BASF is doing it for PR reasons but in doing so, it seems to be aiding the fear-mongering people on the internet. Well, I guess if it will increase their profits, okay. I was a little bit puzzled by them mentioning legislation in regards to all this as it made ethylene oxide reduction from 5ppm to 1ppm or under seem like an actual safety concern. That did seem quite misleading or at least obscure enough to mislead many people who are not as well-read on this topic.

I’m really rummaging through my mind right now thinking of whether to use a phenoxyethanol + sodium benzoate + potassium sorbate blend in my face cream formula or maybe sodium benzoate, potassium sorbate and whatever else except phenoxyethanol or a formaldehyde releaser, without including something at a ridiculously high level like ethanol or glycerin. I do not know if pentylene glycol or hexanediol could be used at small percentages for substantial preservative efficacy. Lastly, I can use Spectrastat OEL. Do you have any insight into this?