The effect of bismuth oxychloride can be called "shiny", so it's probably not the best ingredient for a foundation for those of us with oily or aging skin. However, it is a great ingredient in eye shadows or lipsticks to impart a pearlescent effect or to increase the wear time on these products. As it is hydrophobic, it's awesome for anhydrous products.
Bismuth oxychloride is fantastic texturizer, or ingredient that imparts a silky feeling. You'll often see it described as "creamy" or "silky". If you are into pressing your powders, bismuth oxychloride imparts a very smooth, very even texture - probably the most even texture of all the ingredient we've covered thus far. It will overcome the drag of other ingredients - calcium carbonate, zinc oxide, titanium dioxide - very very well.
For those of you who want to press your powders as it will impart an even, smooth texture. The feeling of this ingredient has been called "creamy", and it has a silky feeling upon application and on your skin.
It is also an anti-bacterial ingredient, so if you like using botanicals - extracts, starches, hydrolyzed proteins - including bismuth oxychloride could increase the shelf life of your products.
It can be used the way you'd use sericite mica, talc, or Micronaspheres - as the main ingredient in your fillers.
SUMMARY OF BISMUTH OXYCHLORIDE
Usage rate: up to 25%
Whiteness or opacity: To make a colour lighter, to cover up imperfections.
Offer some opacity and whitness to your products. It offers good coverage.
Translucency: The base itself is almost invisible once applied.
Isn't that translucent, but isn't really white either.
Does not offer skin protection.
Slip: The product feels nice going on and staying on.
Excellent slip and glide upon application and on your skin. The feeling has been described as "creamy".
Adhesion: The product remains on your skin.
Excellent adhesion and will improve the adhesion of the product overall.
Absorbency: Your colour will remain true throughout the day and not morph into something due to environmental stresses or skin oils.
It loves oils, so it's an excellent absorber.
Light scattering properties: To give your skin a dewy glow.
It scatters light very well and offers a nice glow to your skin with a pearlescent effect. Some say it can hide fine lines and wrinkles, but there is always a chance too much shine can enhance those lines. It is good for skin discolourations.
There is some controversy about using bismuth oxychloride. Some people report itching and prickling when using products with this ingredient, especially in the heat, and this is likely caused by the crystalline shape of the molecule. (This is not because mineral make-up can occlude the skin - moisturizers, liquid foundations, and other products occlude the skin, and they do not have the same effect! For more information on occlusion, please click here).
If you have skin conditions like eczema, rosacea, or acne, if you are heat sensitive, or if you have sensitive skin, bismuth oxychloride probably isn't the best ingredient for you. As with any ingredient, try it before you invest in a large quantity! If you do find you are sensitive to it, make sure you check the composition of your micas - because it imparts a sparkly effect, a lot of micas include bismuth oxychloride.
I could not find one study or reference - apart from people trying to promote their product - that indicates bismuth oxychloride causes cancer.
Regarding bismuth oxychloride and sensitive skin: When I searched on-line, I mainly found the same quotes over and over again (from a dermatologist from Manhattan) from sites trying to sell me on their product that didn't contain bismuth oxychloride. I am dying to know why bismuth oxychloride has this effect on some people's skin - other than the crystalline shape - so you have any links to reliable studies or information on bismuth oxychloride, please let me know by linking it in a comment (so everyone can enjoy it) or e-mailing me (which I'll then link in the comments here). If you use this as an opportunity to post your advertisements for your products on my site, I will mock you.