Preservatives in sugar scrubs and lotions

[Sukida]

Ok, so I’m doing lots of reading and finding conflicting information.
We are starting out and making lotion bars, sugar scrubs and M+P soaps. I want to ensure our products are safe so we are debating on preservatives to use, which are best, and what works best with each product.
I’ve read that tocopheol acetate (Just straight Vitamin E if I understand correctly?) is effective at preventing the oils in our products from going rancid however Optiphen, Germall and Phenonip are all options too.
How do you choose your preservative? What has worked will for you in the past? Can anyone point my in the direction of the science behind what does and doesn’t work?

Thanks in advance!!

 

[ImpKit]

Vitamin E & ROE (Rosemary Oleoresin / Rosemary Oil Extract) are NOT preservatives. They are antioxidants and, yes, can help extend the life of oils and delay rancidity. This is a delay though. It will eventually happen. To that end, make sure the volume you buy your oils in is one you can go through in a reasonable measure of time.

Optiphen, Germall, and Phenonip are preservatives that will inhibit the growth of bacteria.

This article at Brambleberry talks a bit about options.
This article at Humblebee & Me also talks about options.

What little I know for sure is it can depend on exactly what you are trying to preserve and the working temperatures to make the product. Some are water soluble / mixable others aren't. Some will degrade with heat.

 

[amd]

I make lotions and sugar scrubs with Germall Plus as the preservative. I had plate count testing done on the sugar scrubs and lotions that came back with ND (none detected) for the intial testing, and under 100 (one HUNDRED) for the "dirty" samples. [The dirty samples were product that I decanted into an unsterilized bowl and left open in my most used bathroom for 3 days, played around with fingers, left in a windowsill, spilled onto a counter, etc before decanting into the end customer packaging. I did this because I was mildly curious how well the preservative would react to various exposures.] For plate counts anything under 1000 (one THOUSAND) is safe. I documented my experiments with lotions here for two different methods of making lotion.

 

[Sukida]

Wow! That’s quite a thorough exposure test.

I make lotions and sugar scrubs with Germall Plus as the preservative. I had plate count testing done on the sugar scrubs and lotions that came back with ND (none detected) for the intial testing, and under 100 (one HUNDRED) for the "dirty" samples. [The dirty samples were product that I decanted into an unsterilized bowl and left open in my most used bathroom for 3 days, played around with fingers, left in a windowsill, spilled onto a counter, etc before decanting into the end customer packaging. I did this because I was mildly curious how well the preservative would react to various exposures.] For plate counts anything under 1000 (one THOUSAND) is safe. I documented my experiments with lotions here for two different methods of making lotion.