What is Aluminum Sulfate E520? Uses, Safe, Side Effects

What is Aluminum Sulfate E520? Uses, Safe, Side Effects


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Aluminum sulfate, or alum, is a chemical compound often used for water treatment throughout the world. It’s also used in medicines, and in several manufacturing processes. It can be used as an element of food preservative, binding agent, and thickening agent.

Aluminum sulfate is a white powder and is soluble in water. It increases the flow of urine and removes excess body salts that appear due to increased water intake and improper metabolic processes. This article deals with uses, safety, side effects, and precautions with aluminum sulfate.

What is aluminum sulfate?


Aluminum sulfate is a chemical compound with the formula Al2(SO4)3. In its solid state it is called aluminum sulfuric acid, which is similar to but not the same as aluminum sulfate. It exists in both anhydrous and hydrated forms.

The anhydrous form, which is commonly referred to as alum, is a white, odorless powder that is insoluble in water and soluble in alcohol. The hydrated form known as “alums” (or “alumina trihydrate” in the U.S.) dissolves more readily in water than does pure sodium aluminate.

Aluminum sulfate is produced by treating aluminum oxide with sulfuric acid:

Al2O3 + H2SO4 → Al2(SO4)3 + H2O

It can also be prepared by neutralizing aluminum chloride solution with sodium sulfate:

NaCl + Na2SO4 → NaCl + Al2(SO4)3

Aluminum sulfate has many applications. In industry, it is used as a flocculant for suspended particles, such as clay in water treatment, or carbon dioxide gas bubbles in beer brewing or citrus juice processing. This can make the water clear, but it does not remove the suspended particles themselves. It is also used in swimming pools to keep them clean. In agriculture, it is applied as a fertilizer, although its poor solubility means that it must be mixed with other compounds such as urea for application to soil.

What aluminum sulfate is used for?


Aluminum sulfate is a white powder that is used in many industries. In the food industry, it is used as an emulsifier, thickener, and leavening agent. It is also used in water treatment to remove iron, manganese, and other impurities.

In the chemical industry, aluminum sulfate is used in the manufacturing of paper pulp and rayon fibers. It is also used as a flocculating agent in wastewater treatment plants and for extracting gold from ore. Aluminum sulfate may be added to some medicines to make them more soluble or to improve their appearance.

Aluminum sulfate has many other uses as well. It can be used as a fire retardant in rubber products such as tires, hoses, and cables; it can be added to cosmetics as an abrasive; it can be added to toothpaste to make it foam better; it can be added to shampoo or body wash so that they foam when applied to wet hair or skin.

What is aluminum sulfate made of?


Aluminum sulfate is made from the reaction of aluminum oxide with sulfuric acid. The end result is a white powder that is insoluble in water.

Aluminum sulfate is an inorganic compound used as a coagulant, flocculent, and water treatment chemical. It is produced by the reaction of aluminum oxide with sulfuric acid. It is also known as alum or by the trade names Alumina Soluble, Alumina 72, Alumina Soluble Crystals, Aluminium sulphate, Aesalpeter, Alaunox GP1, and Alumpellets.

It can be prepared by adding sulfuric acid to finely divided aluminum metal. Exothermic heat is evolved during this reaction and the temperature must be kept below 60°C (140°F). The resulting mixture of hydrated aluminum sulfate (Al2(SO4)3·18H2O) contains about 10% water of crystallization and has a specific gravity of 2.53 at 20°C (68°F). A solution of this material in water is called alum liquor or alum solution; it acts as an astringent on the skin but does not irritate it like some other astringents.

How aluminum sulfate is made?


Aluminum sulfate is produced primarily from bauxite and cryolite. In general, sulfuric acid reacts with these two minerals to produce it. Al2O3 + 3H2SO4 = Al2(SO4 )3 + 3H2O is the chemical equation for the reaction



It appears as white powder, shining plates, crystalline fragments or colorless solution, and has an astringent taste.

As a result of its hygroscopic characteristics, it easily absorbs moisture and can agglomerate in the air over time.

In addition to dihydrate, it is available in hexahydrate, decahydrate, tetradecahydrate, hexadecahydrate, and octadecahydrate forms.

Other namessulfuric acid, aluminum salt (3:2), aluminum trisulfate
CAS number10043-01-3
Chemical formulaAl2(SO4)3
Molecular weight342.13
PH2.9 or above (5 % solution)
SolubilityWater-soluble, ethanol-insoluble.


Aluminum Sulfate structure


What’s the application of aluminum sulfate?


The aluminum salt aluminum sulfate is one of the most important salts of aluminum. It is primarily used as a coagulant in the purification of drinking water and industrial water, as a soil acidifier in gardening (e.g. changing hydrangea color to blue), and as a sizing agent in papermaking.



However, it has been used as a food additive in Europe under the number E520. It is classified under Commission Regulation (EU) No 231/2012 under “Additives other than colors and sweeteners” and is permitted for use in candied, crystallized or glacé fruit and vegetables, candied cherries, and liquid egg white for egg foams.

FDA also recognizes it as safe when used according to good manufacturing practices in food.

It can be used in food as a firming agent, sequestrant, pH adjuster, and leavening acid for pickling, baking, and cheese.

However, you should be careful when mixing sulfuric acid with water as it can burn skin and eyes.

Coagulant in water treatment


Traditionally, aluminum sulfate has been used to remove phosphorus from lakes and ponds for algae control, in addition to purifying drinking water and wastewater.

Aluminum hydroxide colloids are formed by dissociating aluminum ions in water and reacting with water.

  1. Al2(SO4)3 = 2Al3+ + 3 (SO42-)
  2. Al3+ + 6H2O = 2Al(OH)3 + 6H+

Sulfate anion and aluminum cation are dissociated by aluminum sulfate in water. Due to the positive 3+ charge of the aluminum ion, it easily neutralizes negative charges, such as the negative charges of fluorine, chlorine, and phosphorus. As well as promoting the mutual connectivity and precipitation of colloidal particles through bridging, bonding, and crosslinking.

In the meantime, it forms complexes and Al(OH)3 colloids. By sedimenting Al(OH)3 colloids, which have a large surface area, tiny impurities (e.g. bacteria, colloids, and other suspended solids) that cannot be easily filtered can clump together into large particles. Clarifying the water is the last step.

As a pool clarifier, it can also be used to reduce turbidity in swimming pools.

What is flocculants?


Flocculants are chemicals that cause particles in a liquid to clump together. The result is a substance called a floc, which is easier to remove from the liquid.

Flocculants are used in water treatment systems, such as those at water treatment plants, and also at home to remove sediment and other impurities from water that has been stored in containers for several days.

Flocculants are used to:

  • Remove dirt from water by causing it to clump together so it can be more easily removed from the water;
  • Increase the efficiency of filtration systems by removing suspended solids that would otherwise clog filters;
  • Remove contaminants from wastewater.

Aluminum sulfate for Hydrangea


The colors of hydrangea flowers vary widely due to external environmental factors, including cultivation conditions. Hydrangea has ornamental value as well as commercial value. A popular method for controlling the color of hydrangea flowers is to use aluminum sulfate.

With different concentrations of aluminum sulfate applied to soil for hydrangea cultivation, different colors can be obtained from the combination of red and blue.

In addition to promoting Al3+ absorption by the roots, aluminum sulfate raises Al3+ levels in the petals of the hydrangea, increasing their intensity and purity.



Aluminum sulfate is sometimes added to alkaline soils as a soil acidifier and fertilizer for acid-loving plants such as azaleas, camellias, hemlock, holly, cedar, blueberry, rhododendrons, and gardenias.

When mixed with water, it produces a diluted sulfuric acid solution that alters soil acidity. Using the following equation: Al2(SO4 )3 + 6 H2O – 2Al (OH)3 + 3H2SO4



In addition to speeding up cement setting and hardening, aluminum sulfate can produce a certain strength rapidly by forming fine needle-like ettringite and secondary gypsum, which are intermediate products of cement setting that lead to rapid cement setting.

Sizing agent in Paper manufacturing


In papermaking, Size agents can be made using aluminum sulfate. Fibers are used to make paper (wood pulp or straw pulp), and unsized paper cannot be written on or printed on. Additionally, paper’s strength decreases after absorbing water, affecting its use.

To achieve ink resistance (e.g. writing paper), oil resistance (e.g. food packaging paper) or other purposes, the most paper needs to be coated with water-resistant substances to delay fluid penetration. This process is known as sizing and the added substance is known as a sizing agent.

Other uses


Additionally, aluminum sulfate is used for grease clarifiers, petroleum deodorizers, decolorizers, mordants to improve fabric dye adhesion, leather tanning agents, medical astringents, deodorants, titanium dioxide fillers, and foam agents for fire extinguishers.

Is aluminum sulfate the same as Epsom salt?


No, aluminum sulfate and Epsom salt are not the same.  Aluminum sulfate is a white powder that has many uses, including cleaning, gardening, and medicine.

Epsom salts are magnesium sulfate crystals, which can be used to help treat muscle aches and pains. They also have other medicinal uses.

The two chemicals are similar in appearance but have different chemical makeup and properties.

Aluminum sulfate contains a compound called Alumina (Al2O3). The chemical formula for Alumina is Al2O3. This compound has a molecular weight of 74.92, and it is made up of two atoms of Aluminum (Al) and three atoms of Oxygen (O). The chemical formula for Epsom salt is Magnesium Sulfate (MgSO4). The chemical formula for Magnesium Sulfate is MgSO4. This compound has a molecular weight of 98.08, and it is made up of one atom of Magnesium (Mg), two atoms of Sulfur (S) and four atoms of Oxygen (O).

How much aluminum sulfate to lower ph?


The amount of aluminum sulfate to lower pH depends on the amount of water in your pool. If you have a standard-size pool, then you can use one scoop per 10,000 gallons of water. If your pool is larger or smaller than that, then you may need more or less.

For example: If your pool holds 30,000 gallons and has a pH of 7.5, you would use three scoops of aluminum sulfate to lower the pH to 7.2.

What are the possible aluminum sulfate side effects?


Aluminum sulfate is a salt and an antacid. It’s often used as a food additive.

Aluminum sulfate is safe when used in small amounts and as long as you don’t have kidney failure or other conditions that affect your ability to get rid of excess aluminum.

However, ingesting large amounts of aluminum sulfate can cause side effects such as:

Rashes or irritation of the skin

Redness or swelling of the skin

Dry or chapped skin

Itchiness of the skin

Burning sensation on the skin

Is aluminum sulfate safe?


Aluminum sulfate is a salt of aluminum and sulfuric acid. It’s used in many industrial processes, as a leavening agent in baking, and for water treatment. In humans, it’s often found in cosmetics, antiperspirants, and sunscreens.

The Food and Drug Administration classifies aluminum sulfate as generally recognized as safe (GRAS) when used in small amounts as an anticaking agent in food. But the FDA also says that large amounts can cause nausea, vomiting and diarrhea. The Environmental Protection Agency (EPA) lists it as a hazardous substance because it’s highly water soluble (meaning it dissolves easily in water) and can damage aquatic life by reducing oxygen levels in the water.

The National Toxicology Program (NTP), part of the National Institutes of Health, has shown that aluminum sulfate causes cancer in rats when given orally (swallowed). The NTP also says that people who breathe or swallow high amounts of aluminum sulfate over years may develop lung disease or kidney disease.

Studies show that people who work directly with aluminum sulfate at factories generally have more risk of developing lung disease than those who work elsewhere, but it is not clear whether this is due to the aluminum sulfate itself or other chemicals used in conjunction with it.

In medicine, aluminum sulfate is used as a laxative. It can also be used as an antacid to treat indigestion and heartburn, although it should not be given to children younger than six years old.

Where to buy aluminum sulfate?


It is a good idea to buy aluminum sulfate from a local supplier because the price is usually cheaper. The main drawback is that you will have to pay for shipping.

You can buy aluminum sulfate from Amazon, but you may have to order it because it’s not always in stock. If you’re looking for a more convenient option, you can find it at your local hardware store or home improvement store. The brand name of this product is Amalie Water Treatment Solution, but some brands are called Alum or Alum Powder.

if you want to purchase a large quantity, you can consider purchasing it from Grade Chemical. Grade Chemical is one reliable aluminum sulfate manufacturer in China. they can direct delivery to you by DHL. so you don’t need to worry about delivery. for their aluminum sulfate price is more competitive than you buy in the local market.



As a surface water treatment chemical, aluminum sulfate is very efficient at removing suspended solids – that means inorganic and metal ion impurities. It does this by neutralizing acidity and promoting water coagulation, which allows them to be filtered out of the water by sedimentation or flocculation processes. Sulfates were identified as one of the most common ions in tap water in a study conducted in 2003 and a simple water test can show you if they are present. Sulfate levels can easily be controlled by adding aluminum sulfate to your lake or pond through various methods.

if you have any feedback for the aluminum sulfate additives? Let us know in the below comments.

Sophie Feng

Sophie Feng

Sophie Feng is the author of gradechemical.com, she is the co-founder of the grade chemical network. She has been in grade chemical company since 2017, with a working knowledge of food chemical .

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