Monday, November 1, 2010
Preservatives: Suttocide A
This preservative is made by reacting a mixture of glycine (an amino acid) and sodium hydroxyide in water with formaldehyde. So as you can probably guess, it's a formaldehyde releaser.
This seems like a very picky preservative in that it needs to be added in the cool down phase of your product (below 60˚C), but there are special considerations for different products. For shampoo, body wash, and other surfactanty things, you need to add it at 0.1% to 0.3% when it's below 60˚C but before you thicken it with salt. For conditioners, you want to use it at 0.1% to 0.2%: It can interact with your quats, but it won't be de-activated by them. It's suggested at 0.5% for emulsions - add it when the product is below 60˚C but before you add the fragrance. And if you want to use it to gel your carbomers - read the data sheet for more information!
The different amounts correspond to how hard the product is to preserve. My shampoos and body washes tend to be chock full of botanical ingredients like aloe vera and hydrosols and proteins and extracts, so I'd probably want to use 0.5% just to be on the safe side.
If you are using Suttocide A as your preservative, you might want to check the pH on your final product as it can skew it a bit to the alkaline side of things.
Summary of Suttocide A
INCI: Sodium hydroxymethylglycinate
Usage: 0.1% to 1% in the cool down phase before adding fragrance. (It's approved in the EU at up to 0.5%).
Products must contain some water. Not suitable for anhydrous products.
Good for products with a pH of 3.5 to 12.
Suitable for use as a gelling agent with carbomers due to the high alkalinity of this preservative.