Alumina at a glance

  • Naturally occurring mineral also called aluminum oxide
  • Used as an abrasive, thickener, and absorbent in cosmetics
  • Also functions as a coating agent for some powders, such as titanium dioxide
  • Determined safe as used in cosmetics and medications
  • The primary component of rubies, emeralds, and sapphires

Alumina description

Alumina is the common name of the ingredient aluminum oxide. It is a naturally occurring mineral used as an abrasive, a thickener, and an absorbent in cosmetics. Alumina is sometimes used as part a coating blend for nano-sized mineral UV filters such as titanium dioxide. This coating keeps the very fine power particles of the mineral sunscreen on skin’s surface since the coating materials are a larger molecular size. These coating blends also improve the aesthetics and even application of mineral sunscreen ingredients. In skin care preparations, alumina is used in amounts up to 25%. It’s been determined safe as used in cosmetics by the independent Cosmetic Ingredient Review panel. It is also approved by the U.S. Food and Drug Administration as a colour additive for use in certain over-the-counter drugs. Alumina in its natural form is a white solid. It is the third hardest naturally occurring substance, and is the primary component of rubies, emeralds, and sapphires (their colour is determined by small impurities found in heavy metals).

Alumina references

  • International Journal of Toxicology, November 2016, pages 16S-33S
  • Journal of Nanoscience and Nanotechnology, February 2015, pages 1,636-1,646

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings


Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.


Necessary to improve a formula's texture, stability, or penetration.


Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.


There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.


May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.


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Not rated

We have not yet rated this ingredient because we have not had a chance to review the research on it.