Magnesium sulfate

Additive
Magnesium sulfate in crystal form

INCI
Magnesium Sulfate

Compliant with natural cosmetics

Characteristics

Magnesium sulfate (MgSO4) is the magnesium salt of sulfuric acid and is generally known as "Epsom salt". It is highly hygroscopic, which also accounts for the laxative effect for which it is often taken internally.

In cosmetics, it is mostly used to stabilize water-in-oil emulsions. Since the inner phase in emulsions tends to coalesce - i.e., the dispersed droplets want to flow together - which can lead to complete phase separation, it is recommended to prevent coalescence.

Since water forms the inner phase in W/O emulsions, the addition of electrolytes (salts) can reduce the attraction of the water droplets to one another. Magnesium sulfate also ensures a reduced interfacial tension between water and oil, thus allowing for a denser arrangement of the emulsifier at the interface.

This causes the water droplets to be distributed more finely and to remain so, and it makes W/O emulsions easier to create and more stable.

Furthermore, magnesium sulfate can also be used as a base for bath salts or as a moisture-binding substance in products for skin and hair.

Usage concentration and processing

• 0.5 - 1% stabilizing agent in W/O emulsions and as an active ingredient
• up to 100% in bath salts