A great mineral formula can be achieved with just a handful (3-8) of ingredients - notably Zinc Oxide, Titanium Dioxide, Iron Oxides and Mica. Generally, anything else added is purely to enhance the product's texture, feel and fill. Typically defined by the ingredients that are left out (ie. chemicals, preservatives, parabens, dyes, fragrances), mineral makeup can still cause allergic reactions, skin issues and irritations - because of extra additives, the main common culprits are Bismuth Oxychloride, Boron Nitride & Magnesium Stearate. Other skin irritants you should aim to avoid in mineral makeup are Carmine, Dimethicone (synthetic silicons), Talc and of course avoid Parabens, Sulfates, FDC Lakes & Dyes & Propylene Glycol.
BISMUTH OXYCHLORIDE: A by-product of refined lead and copper! Uggh! Used to achieve a satin, dewy radiance on the skin, as its pearlescent look increases the luminosity of foundations. BUT, it is well known for causing reactions such as itching, rashes, redness, burning, clogged pores (leading to acne/roseacea), enlarged pores and irritated skin. Many companies also use it as a cheap FILLER in their formulas. If you react with mineral makeup, especially with itching and redness, this is the most likely ingredient causing it, so be sure to check the ingredient list!
BORON NITRIDE: A chemical compound of boron and nitrogen, sometimes used as an alternative to Bismuth Oxychloride, as a silky ingredient to give a shimmery, translucent finish to the skin, provide extra glide, skin feel and adhesion and absorb excess oil. It is considered non-toxic, BUT, it can cause itchy rashes with prolonged use plus it can severely dehydrate the skin and make existing dryness worse, If you have sensitive skin, any chemical ingredient could cause a reaction!
MAGNESIUM STEARATE: A common synthetic additive in many mineral formulas to improve slip & adhesion, binding of ingredients and a matte finish. Supposedly considered safe for use, however this ingredient forms a continuous film on the skin which effectively makes it occlusive on the skin - ie. prevents the skin from breathing. Hence it is known to irritate skin, particularly for those with sensitive skin and is often known to cause watery eyes.
BY PUTTING EXTRA THOUGHT INTO YOUR NEXT PURCHASE, YOU CAN AVOID UNNECESSARY ALLERGIC REACTIONS AND UNWANTED SKIN REACTIONS.