Iron Oxides

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What is it? Potent powdered mineral pigments.
Appearance Fine powdered pigment available in brick red, yellow, black, and brown.
Texture Fine, light powder.
Scent Nothing noticeable.
Solubility Insoluble
Why do we use it in formulations? For colour—especially colour that we want to be strong enough to carry over to the skin (cosmetics).
Do you need it? If you want to make cosmetics you absolutely need iron oxides.
Refined or unrefined? The only versions you can purchase are synthesized and refined; while iron oxides do occur naturally there are heavy metal contamination concerns, so the wild-harvested variety is not legal for sale. Learn how they’re made by watching this video.
Strengths Because they’re so strong, only a little is needed (I recommend grabbing Precision Scale and/or a set of these tiny measuring spoons to measure them out accurately).
Weaknesses They’re only available in a handful of very earthy colours—no classic red lipstick shades here, sadly.
Alternatives & Substitutions You can look at synthetic FD&C/D&C lake dyes as an alternative, though those colours are usually significantly brighter—iron oxides are where it’s at for more natural hues (they’re especially necessary for foundation). Dyes are also dyes and will stain the skin. Sometimes this is desired (lip stains, for instance), but sometimes you really don’t want it (eyeliner that stains the skin).

Natural plant powders (ground botanicals, spices, etc.) are not a good alternative to iron oxides; they are far less pigmented and can oxidize over time.

Chromium oxides perform similarly and are available in green and turquoise colours. Ultramarines also perform similarly and are available in bright blue, lavender, and pink. This sampler pack from TKB Trading includes an excellent selection.
How to Work with It As with all fine powders, be sure to wear a dust mask around it if they’re going to become aerosolized (like if you’re whipping it up in a coffee grinder).
Storage & Shelf Life Stored somewhere cool, dark, and dry, iron oxides have an indefinite shelf life.
Tips, Tricks, and Quirks Start with less than you think you need and work your way up to it! I once accidentally made leg lipstick while trying to make a tinted body butter bar. Also, because iron oxides are insoluble they will settle out of liquid concoctions—this means you’ll want to stir oily concoctions to keep oxides suspended until the oils have cooled and thickened enough to support the weight of the oxides.
Recommended starter amount 10–30g (0.35–1oz)
Where to Buy it Buy it from an online DIY ingredient supplier or Amazon. If you’re in the USA (or don’t mind paying international shipping), TKB Trading is an amazing source for pigments.

Some Formulations that Use Iron Oxides

Skills

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Posted on

August 26, 2016