What is a Dead Sea salt bath?
A Dead Sea salt bath is a warm bath with salt from the Dead Sea dissolved in the water. The salt is a mix of minerals, mainly magnesium and potassium chlorides, with far less sodium chloride than table salt. Follow the pack for the amount (as a general guide, start with 100 to 250 g), keep the water warm, not hot, and soak for 15 to 20 minutes.
Quick answer
- What it is: salt collected from the Dead Sea, a landlocked salt lake in the Jordan Rift Valley.
- What is in it: mainly magnesium and potassium chlorides. One analysis lists 31.4% magnesium chloride, 20.9% potassium chloride and 5.37% sodium chloride.
- Epsom salt: a single compound, magnesium sulfate.
- Table salt: at least 97% sodium chloride on a dry basis.
- How much: follow the pack. As a general guide, start with 100 to 250 g in a full bath.
- How to use it: dissolve it in warm, not hot, water and soak for 15 to 20 minutes.
What is Dead Sea salt?
Dead Sea salt is salt collected from the Dead Sea, a landlocked salt lake in the Jordan Rift Valley. Its surface sits roughly 400 metres below sea level, and NASA describes it as the lowest surface feature on Earth.
The salt comes from evaporation ponds. NASA notes that both sodium chloride and potassium salts are produced there, and one supplier describes its bath salt as solar evaporated in a series of ponds, with crystals from off-white to yellowish.
Why is it called the Dead Sea?
It is called the Dead Sea because its high salinity discourages the growth of fish, plants and other wildlife, according to NASA. The lake holds about 350 g of dissolved salts per litre. Sea water holds about 35 parts per thousand, so the lake is roughly ten times saltier.
What is in Dead Sea salt?
Dead Sea salt is mostly magnesium and potassium chlorides, with smaller amounts of sodium and calcium chlorides. One supplier's certificate of analysis for a fine-grain Dead Sea bath salt lists:
- Magnesium chloride: 31.4%
- Potassium chloride: 20.9%
- Sodium chloride: 5.37%
- Calcium chloride: 0.157%
- Moisture: 24%
- Bromide: 3,110 parts per million
- Sulfate: 52 parts per million
Those figures are for one salt, not a standard. A UK listing for another gives 30 to 35% magnesium chloride, 20 to 28% potassium chloride and 3 to 8% sodium chloride, with 32 to 40% water of crystallisation, which is water held within the crystals.
The crystals can feel damp, because magnesium chloride draws moisture from the air, so keep the salt in a dry, airtight container. These figures describe what is in the salt, not what it does.
Is Dead Sea salt the same as Epsom salt?
No. Dead Sea salt is a mix of chlorides, while Epsom salt is one compound, magnesium sulfate.
- Epsom salt: hydrated magnesium sulfate (MgSO₄·7H₂O), named after the spring waters at Epsom in Surrey.
- Dead Sea salt: several chlorides, chiefly magnesium and potassium, with only a small amount of sulfate in the analysis above.
- What they share: both contain magnesium, in different compounds.
Our guide to using Epsom salt in the bath covers that salt in full.
Is Dead Sea salt the same as table salt?
No. Table salt is almost entirely sodium chloride, while sodium chloride is a small part of Dead Sea salt. The Codex standard for food grade salt, which covers table salt, sets a minimum of 97% on a dry basis; the analysis above lists 5.37% for Dead Sea salt. Table salt can also carry anti-caking agents.
Sea salt sits closer to table salt: in sea water, sodium and chloride make up over 90% of the dissolved ions. For the other main types, see our guide on how to choose bath salts.
How much Dead Sea salt should you use?
Follow the directions on your pack, because we found no single official amount. The packs and listings we checked vary widely:
- 6 to 8 tablespoons for a full bath, on one 500 g pack.
- 100 to 250 g for regular use, on one UK listing, which also gives amounts up to 1 kg.
- 250 to 500 g for a full bath, on another listing.
As general guidance, not a rule, start with 100 to 250 g in a full bath and adjust from there.
For scale, Northern Ireland Water puts a bath at 80 litres. On that figure, 250 g makes about 3 g of salt per litre: roughly a tenth of the strength of sea water and a hundredth of the Dead Sea.
How do you run a Dead Sea salt bath?
To run a Dead Sea salt bath, dissolve the salt in warm running water, then soak for 15 to 20 minutes.
- Run the bath warm, not hot, close to body temperature, about 37°C.
- Add the salt under the running tap so it dissolves as the bath fills. Swirl the water with your hand to dissolve any crystals left on the bottom.
- Get in once the salt has dissolved, and keep the water away from your eyes.
- Soak for 15 to 20 minutes, or less if your skin tends to feel dry.
- Rinse if you like, pat dry, and moisturise while your skin is still slightly damp if it tends to feel dry.
Don't bathe when drowsy or after drinking alcohol. If you feel light-headed or too warm, get out slowly: being too hot is one of the causes of fainting listed by the NHS.
Does SLATE use Dead Sea salt?
No. SLATE blocks are made with Epsom salt, not Dead Sea salt, so nothing above describes a SLATE block. Each pressed block is about 22 g, fizzes as it dissolves and contains 10% Epsom salt, about 2.2 g. A Grid™ of 27 blocks is 594 g in all, with about 59 g of Epsom salt.
The SALT block is the plain one in the range: unscented and uncoloured. Every block also contains sweet almond oil, so check each block's ingredient list for allergens. The System explains how blocks combine in a Grid™.
A Grid™ for a plain salt soak
15 SALT · Epsom salt · Unscented
6 CLAY · Kaolin clay · Unscented
6 OAT · Colloidal oat · Unscented
Build this Grid™ →
Common questions
Is Dead Sea salt the same as sea salt?
No. Sodium and chloride make up over 90% of the dissolved ions in sea water, while the Dead Sea bath salts we checked list mainly magnesium and potassium chlorides, with 3 to 8% sodium chloride.
How much Dead Sea salt do you put in a bath?
Follow the pack, as directions vary widely. As general guidance, start with 100 to 250 g in a full bath of warm, not hot, water.
What is the difference between Epsom salt and Dead Sea salt?
Epsom salt is one compound, magnesium sulfate. Dead Sea salt is a mix of chlorides, chiefly magnesium and potassium. Both contain magnesium, in different compounds.
Why does Dead Sea salt feel damp?
It contains magnesium chloride, which draws moisture from the air. Keep it in a dry, airtight container.
Is a Dead Sea salt bath as salty as the Dead Sea?
No. The lake holds about 350 g of dissolved salts per litre. A 250 g bath salt dose in an 80 litre bath makes about 3 g per litre.
How long should you stay in a Dead Sea salt bath?
Stay in for 15 to 20 minutes, in water that is warm, not hot. If your skin tends to feel dry, go shorter.
Sources
- The Dead Sea, NASA Earth Observatory
- Salt Evaporation Ponds, Dead Sea, NASA Earth Observatory
- Dead Sea, Wikipedia
- Extreme fluctuations in ambient salinity select for bacteria with a hybrid "salt-in"/"salt-out" osmoregulation strategy, Ionescu and others, Frontiers in Microbiomes
- Why is the ocean salty?, U.S. Geological Survey
- Epsom Salts, University of Waterloo, Wat on Earth
- Bischofite, SaltWiki, HAWK University of Applied Sciences
- Codex Standard for Food Grade Salt, Codex Alimentarius
- Bathroom, Northern Ireland Water
- Fainting, NHS
SLATE products are cosmetics for external use only. If you have a skin condition, are pregnant, or have any concerns, check with your doctor before use. Patch-test any new product. Keep out of reach of children. Contains essential oils; see each block's ingredient list for allergens. Every block contains sweet almond oil (tree nut).
SLATE is a soak for the body and mind: small-batch bath blocks of cosmetic-grade ingredients, made in the UK. Build your Grid™
