Toluene Inhalation, Toxicity and “Glue Sniffing” Addiction

What is toluene?

Toluene (methyl benzene) is a chemical that is widely used in various substances within the home such as glue, paint and paint removers, and polish. It is also widely used for various industrial purposes. Toluene is volatile meaning that it disperses into the air and can thereby be inhaled. In high doses, it can be toxic. Due to its ability to cross the blood brain barrier and affect the central nervous system, it is an important chemical in everyday substances that can induce as sense of euphoria among other neurological disruption.

What is glue sniffing?

Glue sniffing is a global problem mainly among children. It involves voluntarily inhalation of glue or a rag soaked in glue to induce a sense of euphoria. Glue sniffing is a form of addiction largely due to the effects of the substance toluene within these preparations. Other toluene-containing substances could be used for a similar purpose. However, glue is often the preferred substance because it is easy to access and cheap.

In the long term, glue sniffing has a host of serious effects on every system of the body and can ultimately lead to death. It is not only toluene that has these host of effects on the body. Other chemicals within glue, pain and other household solvents may have a similar effect but toluene is by far the main component responsible for the neurological effects.

Effects of Toluene on the Body

Toluene is a colorless substance with a sweet odor. Small amounts of toluene may have little to no noticeable effect. Toxicity usually starts at blood levels around 2.5mg/L. Levels of 50mg/L and above are often fatal but this also depends on the age, weight and health status of the person. Due to its volatility, it passes into the atmosphere and is therefore easily inhaled. Toluene toxicity can also arise with skin contact and ingestion.

Once it enters the bloodstream, either through the respiratory organs, alimentary tract and transdermal absorption, toluene can reach the brain by crossing the blood-brain barrier. By affecting the transmission of nerve impulses and neurotransmitters (brain hormones), it has a host of central nervous system effects.

However, toluene also affects a host of other systems.

  • Cardiopulmonary :
    – affects electrical activity in the heart.
    – causes the heart muscle to become sensitive to “stress” hormones.
    – narrows the airway by causing constriction of the bronchi.
    – damages the lung tissue.
  • Gastrointestinal :
    – irritation and bleeding from the gut lining.
    – liver inflammation, damage and ultimately failure.
  • Kidney :
    – disturbs the tubular exchange of electrolytes and wastes.
    – proteins lost in the urine.
  • Blood :
    – rise in white blood cells (lymphocytes).
    – rise in eosinophils (eosinophilia).
    – decrease in hemoglobin content in red blood cells (hypochromia).
    – bone marrow failure.
  • Muscles :
    – muscle weakness due to low potassium.
    – muscle breakdown in severe cases.
  • Bones :
    – reduced bone formation.
    – increased bone resorption.

Toluene Exposure Signs and Symptoms

The signs and symptoms of toluene depends on the quantity and duration of exposure.

Acute Exposure

With acute unintentional exposure from toluene-containing household products, symptoms may include dizziness, rapid breathing, shortness of breath, headaches, hallucinations, seizures and even unconsciousness. Milder symptoms pass within minutes to hours after exposure is discontinued. More serious symptoms require immediate medical attention. In the acute setting, there is usually no permanent consequences.

Chronic Exposure

Chronic toluene exposure is mainly due to a “glue sniffing” addiction or occupational exposure. The symptoms also depend on duration of exposure and development of complications. Generalized symptoms that may be noticeable to others include :

  • Low blood pressure
  • Sweetish body odor
  • Rapid breathing
  • Rapid heart rate
  • Paleness (pallor) or even a bluish tinge of the skin (cyanosis)

More organ and system specific signs of toluene exposure includes :

  • Headaches
  • Dizziness
  • Confusion
  • Difficulty concentrating
  • Hallucinations
  • Memory loss
  • Red eyes
  • Burning sensation in the mouth, eyes and throat
  • Difficulty breathing
  • Chest pain
  • Wheezing
  • Nausea
  • Vomiting
  • Jaundice
  • Abdominal pain
  • Muscle weakness
  • Muscle pain

Glue Sniffer’s Rash

Many of the symptoms of acute and chronic toluene exposure can be attributed to various other, and more common, diseases. However, there is usually characteristic skin symptoms associated with touching and handling strong glues and paint that contains toluene. These skin symptoms may not necessarily be due to toluene but instead caused by other chemicals also present in glue and pain.

Firstly there may be dermatitis (a generalized skin rash as a result of skin inflammation) to chemical burns on the skin. Secondly, there may “huffer’s eczema” which is defatting eczema around the mouth. Defatting refers to the loss of fat tissue in an area leading to creasing, cracking and irritation of the skin (irritant contact dermatitis). This arises with chemical exposure. The skin also becomes more prone to secondary infections.

Reasons for Toluene Toxicity and Addiction

Toluene is the main chemical that causes many of the signs and symptoms seen with inhalation of glue and paint. Toluene exposure can be unintentional or intentional.


Unintentional chronic exposure to toluene is mainly seen among workers handling substances that contain the chemical. This is seen among people working in may different occupations. It includes workers handling glue, paint, show polish, gasoline, carpenters and artists.


Unintentional acute exposure is largely accidental where a person inhales or makes skin contact with glues and paints in the home environment without understanding the toxicity of these substances and taking appropriate measures to reduce exposure. Sometimes these substances may be unintentionally ingested, which is mainly seen among infants and young children.


Intentional or deliberate exposure is largely associated with an addiction to glue or paint. It is more common among children and adolescents. A rag is soaked with glue or spray paint and then inhaled. Another common method of administration is to place glue into flimsy plastic bottles and inhaling through the mouth.

Testing for Toluene Toxicity

Various diagnostic tests are conducted to monitor the effects of toluene exposure. Addiction may not be easily attributed to toluene if the abuser does not divulge their glue sniffing habits. Blood tests to measure the levels of toluene in the blood are often a long process and has to be done in specialized laboratories. When addiction is suspected, various tests to detect the use of other more commonly abused substances are often conducted. This includes testing for alcohol abuse, prescription medication and cocaine use.

Treatment for Exposure and Toxicity

There is no specific medication for treating toluene toxicity. Mild to moderate exposure requires no significant measures and symptoms pass in a short period of time. Severe acute and chronic exposure requires supportive measures such as :

  • Oxygen administration.
  • IV administration of fluids and electrolytes as needed.
  • Cardioversion (electric “shock”) to restore normal heart rhythm.
  • Vasopressors, propanolol and esmolol to restore blood pressure and heart rhythm.
  • Gastric lavage (“stomach pumping”) for patients who have ingested toluene-containing substances.
  • Irrigation (“washing out”) of the skin at points of contact with toluene-containing substances.

With proper supportive measures, most patients will recover after acute exposure usually without any complications. However, long term exposure with addiction may lead to permanent complications. In children this is largely seen as learning difficulties.

References :

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