Color range: Natural shades of brown, tan, green, black, red, green and yellow.
Oxidation/fading – No. Not prone to pH sensitivity or darkening/browning
Potency – Very potent. A little goes a LONG way!
Oxides are basically synthetically created versions of natural colorants. While some iron oxides are still extracted naturally, iron oxides in nature are often contaminated by toxic metals such as lead, arsenic, mercury, antimony and selenium. The FDA, which regulates cosmetic colorants, requires that the level of toxic metal present in the colorant be in very low, safe concentrations. In fact, only synthetically prepared iron oxides are approved for use in cosmetics in this country, as explained in Johnson, S.T. & Wordell, C.J. “Homeopathic and herbal medicine: Considerations for formulary evaluation,” Formulary, 32, 1167, Nov. 1997.
Oxides are really, really potent, and a small amount will take you a very long way. They are wonderful to use in CP because they are so potent, the color holds true through saponification, and doesn’t fade in the finished soap, either. Oxides are wonderful for tinting lip balms without throwing off the final product texture as well.
Cosmetic crafters also appreciate that oxides are the same color every time you buy them (unlike botanical colorants which can vary from batch to batch and year to year). They are potent enough to use in products containing zinc oxide or titanium dioxide without getting a very pale end product, and they create a product that holds a true color over time.
Oxides can clump a bit and are not soluble in water. Your best bet is to mix them with a bit of liquid oil before adding them to your product; using a mini frother (like a latte frother) is particularly effective. It can also be helpful to run them through a mini-strainer to eliminate any clumps before adding them to the product.
Oxides are a cost effective, safe and beautiful way to color your products in a variety of natural shades.