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Magnesium sulfate

Chemical Name:
Magnesium sulfate
MgSO4;MAGNESIUM SULPHATE;anhydrous Magnesium sulfate;Sulfuric acid magnesium salt;Salts;Dried;Magnesium sulfate, Pure;sulfuricacidmagnesiumsalt;Magnesium Sulfate, Anhydrous, USP/NF;Magnesium sulfate Vetec(TM) reagent grade
Molecular Formula:
Molecular Weight:
MOL File:
MSDS File:

Magnesium sulfate Properties

Melting point 1124 °C
Density 1.07 g/mL at 20 °C
vapor density <0.01 (vs air)
vapor pressure <0.1 mm Hg ( 20 °C)
storage temp. no restrictions.
solubility H2O: 1 M at 20 °C, clear, colorless
form powder (very fine)
Specific Gravity 2.66
color slightly gray
PH 7.9 (50g/l, H2O, 25℃)
Water Solubility Soluble in water. Slightly soluble in alcohol, glycerol. Insoluble in acetone.
λmax λ: 260 nm Amax: 0.03
λ: 280 nm Amax: 0.02
Sensitive Hygroscopic
Merck 14,5691
Stability Stable. Hygroscopic.
FDA 21 CFR 184.1443; 582.5443; 175.300
CAS DataBase Reference 7487-88-9(CAS DataBase Reference)
NIST Chemistry Reference Magnesium sulfate(7487-88-9)
EPA Substance Registry System Magnesium sulfate (7487-88-9)


Risk and Safety Statements

Hazard Codes  Xi
Risk Statements  36/37/38
Safety Statements  22-24/25-36-26
WGK Germany  1
RTECS  OM4500000
HS Code  28332100
NFPA 704
1 1

Magnesium sulfate price More Price(77)

Manufacturer Product number Product description CAS number Packaging Price Updated Buy
Sigma-Aldrich MX0075 Magnesium Sulfate, Anhydrous powder Meets Reagent Specifications for testing USP/NF monographs GR 7487-88-9 500g $80 2022-05-15 Buy
Sigma-Aldrich MX0075 Magnesium Sulfate, Anhydrous powder Meets Reagent Specifications for testing USP/NF monographs GR 7487-88-9 2.5kg $310 2022-05-15 Buy
Sigma-Aldrich 83266 Magnesium sulfate solution BioUltra, for molecular biology 7487-88-9 100mL $75.7 2022-05-15 Buy
Sigma-Aldrich 83266 Magnesium sulfate solution BioUltra, for molecular biology 7487-88-9 500mL $264 2022-05-15 Buy
Sigma-Aldrich 63136 Magnesium sulfate puriss.p.a.,dryingagent,anhydrous,≥98.0%(KT),powder(veryfine) 7487-88-9 250g $103 2022-05-15 Buy
Product number Packaging Price Buy
MX0075 500g $80 Buy
MX0075 2.5kg $310 Buy
83266 100mL $75.7 Buy
83266 500mL $264 Buy
63136 250g $103 Buy

Magnesium sulfate Chemical Properties,Uses,Production


Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen, with the formula MgSO4. It is strongly hygroscopic and often encountered as the heptahydrate sulfate mineral epsomite (MgSO4•7H2O), commonly called Epsom salt. And the monohydrate, MgSO4•H2O, is found as the mineral kieserite.
Magnesium sulfate
In gardening and other agriculture, magnesium sulfate is used to correct a magnesium or sulfur deficiency in soil.
In food preparation, magnesium sulfate is used as a brewing salt in beer production or used as a coagulant for making tofu.
In chemistry, anhydrous magnesium sulfate is commonly used as a desiccant in organic synthesis due to its affinity for water.
For Marine use, magnesium sulfate heptahydrate is used to maintain the magnesium concentration in marine aquaria which contain large amounts of stony corals.
For medicine use, it is used in pregnant women to control seizures due to certain complications of pregnancy (eg, severe toxemia) and to control high blood pressure, severe brain function problems (encephalopathy), and seizures in children who have sudden, severe inflammation of the kidneys (acute nephritis). Besides, magnesium sulfate is also used as a laxative to relieve occasional constipation.

Chemical Properties

Magnesium sulfate (MgS04) is a colorless crystal with a bitter, saline taste. It is soluble in glycerol and used in fireproofing, textile processes, ceramics, cosmetics, and fertilizers.

Chemical Properties

Magnesium Sulfate is found widely in nature as either a double salt or as a hydrate, colorless crystals,very soluble in water, soluble in glycerol, sparingly soluble in alcohol.

Physical properties

In their hydrated form, these salts have a pH of 6.0 (5.5 to 6.5) in solution. These magnesium sulfates are white crystalline solids. Their densities are: 2.66 g/cm3 (anhydrous); 2.445 g/cm3 (monohydrate); 1.68 g/cm3 (heptahydrate). Solubilities in water are: anhydrous= 26.9 g/100 ml (0°C); monohydrate= 25.5 g/100 ml (20°C); heptahydrate=71 g/100 ml (20°C). Magnesium sulfate is found in nature in many salt deposits and mineral waters, occurring as hydrates or double salts. The heptahydrate or Epsom salt was discovered in 1695, found inthemineralwater at Epsom. Kieserite and epsomite are the two most important minerals. Other than these and the above hydrates, magnesium sulfate is also found in several other minerals, including langbeinite, leonite,vanthoffite,bloedite,kainite,polyhalite,


In agriculture and gardening, magnesium sulfate is used to correct magnesium deficiency in soil, since magnesium is an essential element in the chlorophyll molecule. It is most commonly applied to potted plants, or to magnesium-hungry crops, such as potatoes, tomatoes, peppers, and roses. The advantage of magnesium sulfate over other magnesium compounds (such as dolomitic limestone) is its high solubility. MgSO4 has been used in organic synthesis to remove water from nonaqueous solutions before the organic reaction is started. Since it is insoluble in most organic solvents, its addition forms hydrates that can be easily removed.
Epsom salt is also used to prepare footbaths, intended to soothe sore feet. The reason for the inclusion of the salt is partially cosmetic. However, magnesium sulfate can also be absorbed into the skin, reducing inflammation. It is also sometimes found in bottled mineral water, and accordingly is sometimes listed in the contents thereof. Magnesium sulfate heptahydrate is also used to maintain the magnesium concentration in marine aquaria which contain large amounts of stony corals as it is slowly depleted in their calcification process, precipitation into calcium carbonate. Oral Epsom salt is used as a saline laxative as well as for replacement therapy in “hypomagnesaemia” (lack of Mg2+) in animals and humans. Magnesium sulfate paste has been used as an agent for dehydrating (drawing) boils, carbuncles or abscesses. Magnesium sulfate solution has also been shown to be an effective aid in the fight against blemishes and acne when applied directly to problematic areas. Magnesium sulfate, when used through soaking, can soothe muscle pains and help improve rough patches in the skin. Soaking in a warm bath containing Epsom salt (magnesium sulfate) can be beneficial to soothe and relieve herpes outbreak symptoms, such as itching and lesions relating to genital herpes or shingles.


Magnesium sulfate is suitable for sensitive molecular biology applications. It used as a component of bath salts and beauty product. It is utilized by the athletes to soothe sore muscles and effective in the removal of splinters. It is commonly used as a desiccant in organic synthesis due to its affinity for water. It acts as a brewing salt in beer production to adjust the ion content of the brewing water as well as enhance enzyme action. It plays a vital role as an antidote for barium chloride poisoning. . It is useful in controlling seizures associated with epilepsy, glomerulonephritis, or hypothyroidism.


Magnesium sulfate is used widely in several industries including fertilizer, cement, textile, chemicals, and medicine. In the cement industry, it is used in manufacturing oxysulfate cement. In medicine, it is an analgesic and cathartic. An important application of anhydrous magnesium sulfate in the laboratory involves drying organic solvents required for syntheses and GC analysis.
In the textile industry, magnesium sulfate is used in finishing composition for dressing cotton; for weighting and sizing silk; as a mordant for fixing basic dyestuffs on wool; and in fireproofing fabrics. It also is a component of certain types of electrolytic plating baths; of various photographic solutions; of cosmetic lotions. It is a catalyst carrier; a dietary supplement in cattle feed; a coagulant for rubber and plastic; and is used in making citric acid and several magnesium salts, such as magnesium stearate.


Hydrated magnesium sulfate occurs in nature as the minerals kieserite and epsomite. The salt is mined in large scale from these and other naturally occurring minerals. The salt also is prepared in the laboratory by the action of sulfuric acid on magnesium oxide, hydroxide, or carbonate followed by evaporation and crystallization:
MgO + H2SO4 → MgSO4 + H2O
Mg(OH)2 + H2SO4 → MgSO4 + 2H2O
MgCO3 + H2SO4 → MgSO4 + CO2 + H2O
Crystallization at temperatures between 1.8 and 48°C yields heptahydrate, MgSO4•7H2O. Below 1.8°C, a dodecahydrate , MgSO4•12H2O crystallizes out. Above 48°C crystals of lower hydrates form. The anhydrous salt is obtained by heating the heptahydrate at about 500°C in a rotary drum; or dehydrating above 150°C in the presence of sulfuric acid.


ChEBI: A magnesium salt having sulfate as the counterion.


Magnesium sulfate prevents convulsions in preeclampsia and directly uncouples excitation–contraction in myometrial cells through inhibition of cellular action potentials. Furthermore, magnesium sulfate decreases calcium uptake by competing for its binding sites, activating adenylyl cyclase (thereby reducing intracellular calcium), and stimulating calcium-dependent adenosine triphosphatase (ATPase), which promotes calcium uptake by the sarcoplasmic reticulum. Magnesium is filtered by the glomerulus, so patients with low glomerular filtration will have low magnesium clearance. Although the compound does have some cardiac side effects, magnesium sulfate may be preferred over β- adrenergic agents in patients with heart disease, diabetes, hypertension, or hyperthyroidism.


Magnesium sulfate is utilized in the potassium chemicals industry for the manufacture of potassium sulfate (from potassium chloride), sodium sulfate and potash magnesia (potassium magnesium sulfate). Magnesium sulfate, particularly as kieserite, is used as a fertilizer (ca. 80% of total consumption). It is also used in the textile industry, in the manufacture of building and refractory materials, in the pulp industry and in the production of animal feedstuffs and motor oil additives.

Production Methods

Magnesium sulfate is widely distributed in nature, e.g. in salt deposits as kieserite, as Epsom salt MgSO4 . 7H20, in the form of double salts such as kainite 4KCl . 4MgSO4 . 11H20 and langbeinite K2SO4 . 2MgSO4, and in brines. Large quantities of kieserite, Epsom salt and anhydrous magnesium sulfate are produced in the processing of potassium salts. Magnesium sulfate is also produced by reacting magnesium carbonate or seawatermagnesium hydroxide with sulfuric acid.

Biological Functions

Magnesium sulfate may be effective in terminating refractory ventricular tachyarrhythmias, particularly polymorphic ventricular tachycardia. Digitalis-induced arrhythmias are more likely in the presence of magnesium deficiency. Magnesium sulfate can be administered orally, intramuscularly, or, preferably, intravenously,when a rapid response is intended.The loss of deep tendon reflexes is a sign of overdose.

General Description

Magnesium sulfate is an anhydrous magnesium salt.

Agricultural Uses

Magnesium sulphate is a white compound existing both in anhydrous (rhombic) and hydrated crystalline forms. The monohydrate MgSO4·H2O (monoclinic) occurs in nature as kieserite. It is a greyish-white crystalline powder which contains about 16 % magnesium and is used as a fertilizer. It is regarded as a concentrated form of epsom salt, having less water of crystallization. The commonest hydrate is heptahydrate MgSO4·7H2O(also called rhombic or epsom salt) which occurs naturally as the mineral epsomite. It is a white powder with a bitter, saline taste. The salt in the monocliic form loses its structural water at 150°C, while the rhombic form loses water at 200°C.
Magnesium sulphate is used in sizing and freproofng cotton and silk, in tanning leather, in the manufacture of fertilizers, in explosives and matches, in medicines as a laxative, and as a veterinary medicine for the treatment of inflammations and infected wounds.

Biochem/physiol Actions

Magnesium sulfate has anti-convulsant, anti-inflammatory and vasodilatory properties. Magnesium sulfate relaxes smooth muscles. In acute asthma patients, use both intravenous and nebulization of magnesium sulfate as additive treatment improves pulmonary function. Magnesium sulfate reduces preterm labor in high risk pregnant women.

Clinical Use

There is much debate as to the efficacy of magnesium sulfate. For effective inhibition of uterine activity, enough must be given to maintain a blood plasma level of at least 5.5 mEq/L. Even at this level, tocolysis may be hard to achieve.

Side effects

The side effects of magnesium sulfate administration are dose dependent. As magnesium levels increase, skeletal muscle weakness increases and CNS depression and vascular dilation occur. Magnesium sulfate infusion commonly results in a slight decrease in blood pressure during epidural anesthesia.
Cardiac muscle is not affected to a clinically evident degree when magnesium is administered at therapeutic levels, although magnesium can have profound myocardial effects during a gross overdose.
Magnesium antagonizes the vasoconstrictive effect of α-agonists, so ephedrine and phenylephrine are likely to less effectively increase maternal blood pressure when administered concomitantly with magnesium.
Magnesium is eliminated unchanged by the kidneys. In a patient who is receiving a maintenance infusion of magnesium and who has decreasing urine output, blood levels of magnesium quickly increase, as do related side effects.
Other side effects of magnesium sulfate include the following: (1) Cutaneous vasodilation with flushing (2) Headache and dizziness (3) Nausea (4) Skeletal muscle weakness (5) Depression of deep tendon reflexes (6) Respiratory depression (7) ECG changes

Safety Profile

A poison by intravenous route. Moderately toxic by ingestion, intraperitoneal, and subcutaneous routes. Human systemic effects: heart changes, cyanosis, flaccid paralysis with appropriate anesthesia. An experimental teratogen. Mutation data reported. Potentially explosive reaction when heated with ethoxyethynyl alcohols (e.g., l-ethoxy 3-methyl-1-butyn-3-01). When heated to decomposition it emits toxic fumes of SOx. See also SULFATES.

Purification Methods

Crystallise it from warm H2O (1g/mL) by cooling. Dry the heptahydrate (Epsom salt) at ~250o until it loses 25% of its weight. Its solubility in H2O is 36% at 20o, 55% at 60o and 74% at 100o; above 110o the solubility decreases with rise of temperature. Store it in a sealed container.


Magnesium sulfate is not for use in patients with heart block or extensive myocardial damage. Use it with caution in patients with impaired renal function, in digitalized patients, and with concomitant use of other central nervous system depressants or neuromuscular blocking agents. Intravenous administration is contraindicated during the 2 hours preceding delivery. Oral administration is contraindicated in patients with abdominal pain, nausea, vomiting, fecal impaction, or intestinal irritation, obstruction, or perforation.



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View Lastest Price from Magnesium sulfate manufacturers

Image Release date Product Price Min. Order Purity Supply Ability Manufacturer
2022-04-02 magnesium sulfate
US $300.00 / kg 10kg 99% 500kg/month HEBEI YINGONG NEW MATERIAL TECHNOLOGY CO.,LTD
2022-03-19 magnesium sulfate
US $1.00 / kg 1kg 99% 10tons Henan Guange Biotechnology Co. LTD
2022-02-25 Magnesium sulfate
US $10.00 / KG 1KG 99% 500tons/month Shanxi Naipu Import and Export Co.,Ltd
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  • 99%

Magnesium sulfate Spectrum

Magnesium sulfate puriss. p.a., drying agent, anhydrous, >=98.0% (KT), powder (very fine) Magnesium sulfate Vetec(TM) reagent grade DTTP 100MM SOL'N PH7.0 FTM + RESAZURINE ACC.HARM PHARM 10X100ML MAGNESIUM SULPHATE XH2O MES-SDS BUFFER 20X TBS TABLETS TRIS-ACETATE-SDS BUFFER 10X Magnesium sulfate, anhydrous, 99.5% Magnesium sulfate anhydrous for analysis EMSURE MAGNESIUM SULFATE ANHYDROUS*CELL CUL Magnesium sulfate anhydrous, free-flowing, Redi-Dri, reagent grade, >=97% MAGNESIUM SULFATE SOLUTION 1M MOLECU Magnesium sulfate, anhydrousUSP, 99.0-100.5% (Titration: after ignition) Magnesium Sulfate, Anhydrous, USP/NF Magnesium Sulfate, EMSURE?, For Analysis Magnesium sulfate, sterile Magnesium sulfate, Pure Magnesium Sulfate Heptahydrate Solution, 2.25% Magnesium sulfate, anhydrous, anhydrous (Monohydrate) kieserite Hair salt Kieserite [as monohydrate] Magnesium sulfate (1:1) Magnesium(II) sulfate magnesiumsulfate(1:1) Magnesiumsulfate,anhydrous MgSO4 Sal amarum Sal anglicum Sal catharticum Sal seidlitense salangalis saldesedlitz Salts Salts of england Sel d'angleterre Sulfuric acid magnesium salt Sulfuric acid magnesium salt (1:1) Sulfuricacid,magnesiumsalt(1:1) sulfuricacidmagnesiumsalt sulfuricacidmagnesiumsalt(1:1) MAGNESIUM SULFATE ANHYDROUS CELL CULTURE REAGENT 99.5% MagnesiumSulphate7H2OUsp MagnesiumSulphate,Dried,Gpr MagnesiumSulphate7H2OIp MagnesiumSulphateDriedAr MagnesiumSulphate7H2OBp MagnesiumSulphateDriedBp Dried Magnesiumsulfateanhydrate Magnesium sulfate, anhydrous, pure, 97% MAGNESIUM SULFATE, ANHYDROUS REAGENT Magnesiumsulfate,anhydrous,99+% MAGNESIUMSULFATE,ANHYDROUS,POWDER,CP MAGNESIUMSULFATE,ANHYDROUS,POWDER,REAGENT MAGNESIUMSULFATE,USP MAGNESIUMSULFATE,USP(BULK