Epsom Salt, Magnesium Sulfate, 1 kg

Epsom salt is magnesium sulphate in chemically pure cosmetic quality from European production. It is a key raw material for bath salts, bath bombs and salt scrubs and in formulations it serves as the active ingredient of the water phase. It is most commonly used in a relaxing bath, where it dissolves in water and gives it a mineral character.

Unlike sea or table salt, this is not sodium chloride but a magnesium salt. After bathing it therefore leaves no feeling of a salty film on the skin. It is fragrance-free, free of perfume allergens, preservatives and ingredients of animal origin, making it a neutral base that anyone can customise according to their own recipe.

Key benefits

• A bath with tradition – magnesium sulphate has been used in baths for a long time. A warm bath with dissolved salt is perceived as pleasant and relaxing, which is why it forms the basis of most relaxing bath blends.
• Does not burden the skin – after rinsing it leaves no film or stickiness. Suitable for the whole body, hands and feet, for example in a foot bath.
• Neutral raw material – no colour, no fragrance and no added substances. It does not alter the scent or shade of the finished product and allows essential oils, herbs or colourants to stand out.
• Readily soluble in water – it dissolves faster in warm water, so no undissolved granules remain in the bath.
• Mineral origin – no GMO, no nanomaterials and no microplastics, which makes it easy to include in clean formulations.

Use in formulation

Epsom salt is used in dry form or dissolved in water. In bath salts it is simply mixed with other salts, dried herbs and the chosen fragrance. Essential or fragrance oils are recommended to be first blended with a small amount of salt, or with a solubiliser, so that they disperse evenly throughout the mixture.

In bath bombs it forms part of the dry phase alongside sodium bicarbonate and citric acid. As a guideline it is added at a proportion of up to approximately 20 % of the mixture. At higher amounts the mass compacts less well and the bomb may be more fragile. Finely milled salt binds better than coarse crystals.

In oil-based salt scrubs it serves as the abrasive component. Since salt is water-soluble, the scrub must be anhydrous and protected against water entering the packaging. Otherwise the crystals will gradually dissolve and the product will lose its scrubbing effect.

In aqueous and emulsion systems it is important to consider that magnesium sulphate is an electrolyte. In W/O emulsions it is sometimes used at a low dose to improve stability. Conversely, in gel systems thickened with electrolyte-sensitive polymers (such as carbomers) it will cause a drop in viscosity. Compatibility should always be verified in the finished formulation.

Suitable for products such as

• Bath salts – on their own or blended with sea or Himalayan salt, herbs and essential oils.
• Bath bombs and effervescent bath tablets – as part of the dry blend for mineral content.
• Foot baths – dissolved in warm water as a base for a home pedicure.
• Body salt scrubs – in anhydrous oil-based scrubs as the abrasive component.
• Shower salts and powdered bath milks – in combination with dried milk, clays or plant powders.

What is good to know

Magnesium sulphate in this form contains water of crystallisation and also readily absorbs moisture from the air. In an open container or in a humid environment it clumps together; the lumps can be crushed or sieved before use. In bath bombs the moisture content of the salt is particularly important because excess water in the mixture can trigger the effervescent reaction before use.

When heated, the salt releases its water of crystallisation and changes structure, so it is added to blends cold, without heat treatment. If a solution is needed, it is prepared by dissolving in water at room temperature or slightly warm temperature.

When colouring bath salts, water-soluble dyes are applied to dry crystals in a small amount of liquid and the mixture is then left to dry. Otherwise the salt will absorb moisture and clump together.

Frequently asked questions