Question 1

What does Magnesium hydroxide do in a cosmetic formula?

Accepted Answer

This ingredient is used mainly as a pH adjuster and alkalizing agent, with secondary roles as an absorbent and opacity booster in creams, deodorants, and oral-care products.

Question 2

Is Magnesium hydroxide clean?

Accepted Answer

From a clean-beauty perspective, it is generally viewed as low concern, non-sensitizing, and not a common allergen. The main formulation caveat is alkalinity, since high levels or poorly buffered systems can feel drying or irritating on skin.

Question 3

Is Magnesium hydroxide sustainable?

Accepted Answer

This material is mineral-derived, commonly sourced from brines, seawater, or mined mineral feedstocks. It is inorganic rather than biodegradable, but it does not behave like persistent synthetic organics and can neutralize into common mineral salts in wastewater systems.

Question 4

Is Magnesium hydroxide COSMOS-approved?

Accepted Answer

It is generally compatible with COSMOS-natural and COSMOS-organic formulas as an allowed inorganic/mineral ingredient, though it does not count as organic content. Its Green Chemistry profile is favorable when sourced with responsible mineral processing, due to simple chemistry, low volatility, and no need for complex petrochemical synthesis.

Question 5

How does Magnesium hydroxide work chemically?

Accepted Answer

This compound is an inorganic alkaline solid with very low water solubility, so it raises pH gradually rather than dissolving like a strong soluble base. It is most often used at low percentages for pH control or absorbency, and formulators need to account for grittiness, dispersion quality, and compatibility with acidic actives or anionic systems.