1,4-Dioxane

Some liquids are used in big factories.

This liquid has a sweet smell. It is used to make things like ink and glue. It can also be found in soaps and shampoos.

Sometimes, tiny bits of it get into our drinking water. This can be bad for our health. Because of this, leaders watch it very closely. It is important to keep our water clean and safe.

1,4-Dioxane is a clear liquid. It has a faint, sweet smell.

People use it in many ways. It helps make inks and glues. It is also used as a solvent. A solvent is a liquid that can dissolve other things. Factories use it to help move chemicals in metal containers. It helps stop some bad changes from happening in the metal.

Sometimes, dioxane is found in small amounts in soaps and shampoos. It is made during a way of making cleaning agents. This way is called ethoxylation. Because of this, it can end up in things like perfumes and toothpaste.

We must be careful with dioxane. It can be harmful to people. It can cause problems for the liver or kidneys. It is also a potential carcinogen. This means it might cause cancer. Many governments watch it very closely. They check the air and the drinking water. In New York, the law sets strict limits on how much can be in water. We want to keep our water and our bodies safe.

1,4-Dioxane is a clear liquid with a faint, sweet smell. It belongs to a group of chemicals called ethers. People often call it simply dioxane because other versions are rare. It is very good at mixing with water. This makes it quite different from other similar liquids. It is also used as a solvent. A solvent is a substance that can dissolve other materials.

This chemical has several important jobs in factories. It acts as a stabilizer for moving chemicals in aluminum containers. Without it, the chemicals might react poorly with the metal. It also works well as a solvent for making inks and glues. Some processes use it instead of other liquids like tetrahydrofuran. This is because dioxane has a higher boiling point. A higher boiling point means it stays liquid at higher temperatures.

Scientists have studied dioxane for a long time. A professor named Agostinho Vicente Lourenço discovered it in 1860. He first called it ether of glycol. Later, a scientist named C. A. Wurtz studied it in 1863. He gave it the name dioxyethylene. In 1906, Alexey Favorsky figured out its exact structure. He also helped find a way to make it using acid. Since the 1920s, factories have used this method to produce it.

There are many interesting numbers regarding its use and history. In 1985, the world produced between 11,000 and 14,000 tons of it. In 1990, the United States produced between 5,250 and 9,150 tons. It can be found in small amounts in many common items. Traces often appear in shampoos, perfumes, and even toothpastes. This happens during a step called ethoxylation. This step helps make cleaning agents foam better and feel less harsh.

We must handle dioxane with great care because it can be dangerous. It is a flammable substance that can produce toxic vapors. Breathing these vapors can irritate your eyes or lungs. It can also cause harm to the liver or kidneys. Because it might cause cancer, many governments monitor it closely. In 2024, the U.S. EPA called it a probable human carcinogen. New York has even set strict limits for dioxane in drinking water.

1,4-Dioxane is a colorless, heterocyclic organic compound. In chemistry, a heterocyclic compound is a ring-shaped molecule that contains atoms other than carbon. This specific substance belongs to a group of chemicals called ethers. It has a faint, sweet odor that is similar to diethyl ether. Most people simply call it dioxane. This is because other versions, known as isomers, are rarely seen in practice.

The molecule is quite flexible in its shape. It can move between two different forms called the chair conformation and the boat conformation. Because these shapes change easily, the substance is often used as an internal standard in nuclear magnetic resonance spectroscopy. This is a scientific method used to study the structure of molecules. Dioxane is also considered one of the smallest crown ethers. A crown ether is a type of molecule that can trap certain metal ions.

Industrially, dioxane is produced through a specific chemical process. Since the 1920s, factories have used the acid-catalyzed dehydration of diethylene glycol to make it. Diethylene glycol is itself obtained through the hydrolysis of ethylene oxide. This method was developed in 1906 by Alexey Favorsky. He was also the scientist who determined the exact structure of the dioxane molecule. During the 1980s, global production capacity reached between 11,000 and 14,000 tons. In 1990, the United States alone produced between 5,250 and 9,150 tons.

One major use for dioxane is as a stabilizer. In the 1980s, most production was used to stabilize 1,1,1-trichloroethane. This chemical is often transported in aluminum containers. Normally, aluminum is protected by a thin layer called a passivating oxide layer. If this layer is disturbed, the metal reacts with trichloroethane. This reaction creates aluminum trichloride, which causes the remaining chemical to break down. Dioxane prevents this by forming an adduct with the aluminum trichloride. An adduct is a product formed by the combination of two substances.

Dioxane is also a versatile aprotic solvent. This means it is a liquid that can dissolve many substances without donating protons. It is used in the manufacturing of inks, adhesives, and cellulose esters. Some industries use it instead of tetrahydrofuran, also known as THF. Dioxane is preferred in some cases because it has a higher boiling point. Its boiling point is 101 °C, while THF boils at only 66 °C.

While some ethers do not mix well with water, dioxane is miscible. This means it can dissolve in water in any proportion. It is also hygroscopic, which means it can absorb moisture from the air. When mixed with water in a specific mass ratio of 17.9 to 82.1, it forms a positive azeotrope. This is a mixture that boils at a constant temperature of 87.6 °C. The oxygen atoms in the molecule are weakly Lewis-basic. This allows it to form adducts with various Lewis acids.

Despite its uses, dioxane is a hazardous contaminant. It is highly flammable and can produce toxic vapors when heated. These vapors can irritate the eyes and the respiratory tract. High levels of exposure in the air can injure the nasal cavity, liver, or kidneys. There is also an explosion hazard. If dioxane is exposed to air for a long time, it can form explosive peroxides. This makes the process of distillation very dangerous if not handled correctly.

Traces of dioxane are often found in consumer products like shampoos, perfumes, and toothpastes. This happens because of a process called ethoxylation. This process is used to make cleansing agents, like sodium laureth sulfate, less abrasive and better at foaming. However, dioxane can appear as a byproduct of this reaction. In the past, levels in cosmetic products reached as high as 279 ppm. Because of health concerns, many manufacturers now use vacuum or steam stripping to remove it.

Environmental safety is a major concern for many governments. Dioxane is considered a potential carcinogen, which is a substance that may cause cancer. The IARC classifies it as a Group 2B carcinogen. In 2024, the U.S. Environmental Protection Agency labeled it a probable human carcinogen. It can contaminate groundwater through manufacturing runoff or waste disposal. In 2010, dioxane was found at 67 different sites in New Hampshire. Some sites showed concentrations as high as 11,000 ppb. To protect people, the State of New York set a strict drinking water limit of 1 part per billion.