Silk Naturals

I recently learned that Sodium Benzoate, although safe on its own, when combined with Vit C and similar acids can produce the carcinogen Benzene.
I just wanted to ask about this since I know some of the serums, including the Mama's Helper that I use, have both Sodium Benzoate and Vit C.
I know there are various forums of Vit C, and the one in the serum is not the typical ascorbic acid, but instead magnesium ascorbyl phosphate. I am assuming those are different. And so I wanted to ask how this type of Vit C reacted with the Sodium Benzoate.
Thank you.

You are correct- they are very different forms of vitamin c. Ascorbic acid has a low pH so it stings on your skin, and it oxidizes pretty quickly. Magnesium ascorbyl phosphate is very stable, and has a much higher pH.

In our finished products the concentration of sodium benzoate is less than .1%- legally I don't even have to declare that it's in there, but that's not how we roll.

I like sodium benzoate because it is food safe, and it's an effective preservative against molds, and fungus even at a very low usage rate. We use preservatives to make safe products- I've seen reports of people actually dying from using improperly preserved products, and it's something I feel very strongly about. While I wouldn't use it to preserve an ascorbic acid vitamin c product I do feel that it's safe to use along with the magnesium ascorbyl phosphate.

As always, I leave it up to you to decide, but for me, and for SN I think it's very safe. Here's a link to the wiki article:
http://en.wikipedia.org/wiki/Sodium_benzoate
http://en.wikipedia.org/wiki/Benzene_in_soft_drinks

Thank you for clarifying Karen

I did a lot of researching last night on it and found this great and thorough article:
http://blog.salonnaturalsonline.com/201 ... -cancer-2/

Sounds like a lot of conditions need to be met for benzene to form, like:

"Benzene production drops sharply at pH levels of between 3 and 5 and laboratory tests indicate that benzene does not form at pH 7."

What Ph are the serums? I'm assuming a higher Ph since skin I think is 6, and anything too low would sting.

Overall it sounds like the chances of the serums forming any benzene are virtually zero

Not Karen, but skin is 4.5-5.5 just Like hair.

The article also mentions that pairing the Sodium Benzoate with Gluconoacetone stabilizes it even more.

And rymorg 2 is right, healthy skin is usually around 5.

Great article link!!! FWIW the WHO says that up to 10 parts per million is safe in drinking water, and you get the most exposure when you're pumping gas, but I don't want to add to anyone's exposure to it.

The pH of the serums varies a little depending on the other ingredients. They're all between 5.5-7. Heat is another variable in the reaction, and we don't heat any of the Vitamin C serums either.

Preservative systems are tricky- it requires a lot of research, and testing to make sure they match well with the products you're making, and not toxic. I researched for about 2 years before I settled on the one that we use (I started working on skin care almost immediately). I felt really comfortable with it at the time, and going on 4 years later I'm still glad we use it.