Toluene (methylbenzene, toluol, phenylmethane) is an aromatic hydrocarbon commonly used as an industrial solvent for the manufacturing of paints, chemicals, pharmaceuticals, and rubber. Toluene is found in gasoline, acrylic paints, varnishes, lacquers, paint thinners, adhesives, glues, rubber cement, airplane glue, and shoe polish.
Toxicity can occur from unintentional or deliberate inhalation of fumes, ingestion, or transdermal (skin) absorption. Toluene abuse or "glue sniffing" has become widespread, especially among children or adolescents, because it is readily available and inexpensive. Toluene is commonly abused by saturating or soaking a sock or rag with spray paint, placing it over the nose and mouth, and inhaling to get a sensation of euphoria, buzz, or high.
- Toluene health conditions include: Acute intoxication from inhalation is characterized by rapid onset of CNS symptoms including euphoria, hallucinations, delusions, tinnitus, dizziness, confusion, headache, vertigo, seizures, ataxia, stupor, and coma. Chronic conditions include: CNS sequelae include neuropsychosis, cerebral and cerebellar degeneration with ataxia, seizures, choreoathetosis, optic and peripheral neuropathies, decreased cognitive ability, anosmia, optic atrophy, blindness, ototoxicity, and deafness.
- Toluene has direct negative effects on cardiac automaticity and conduction and can sensitize the myocardium to circulating catecholamines. "Sudden sniffing death" secondary to cardiac arrhythmias has been reported. Pulmonary effects include bronchospasm, asphyxia, acute lung injury (ALI), and aspiration pneumonitis.
- Gastrointestinal symptoms from inhalation and ingestion may result in abdominal pain, nausea, vomiting, and hematemesis. Hepatotoxicity manifests with ascites, jaundice, hepatomegaly, and liver failure. A rare form of hepatitis—hepatic reticuloendothelial failure (HREF)—has been reported with toluene exposure. With the widespread abuse of volatile substances in young adults today, (hepatitis secondary to toluene toxicity), not just infectious causes, should be considered in the differential diagnosis in the younger patient population who present concerning symptoms.
- Reported renal toxicity from toluene exposure includes: renal tubular acidosis (RTA), hypokalemia, hypophosphatemia, hyperchloremia, azotemia, sterile pyuria, hematuria, and proteinuria.
- Hematologic consequences of exposure may include: lymphocytosis, macrocytosis, eosinophilia, hypochromia, and basophilic stippling, and in severe cases, aplastic anemia.
- Cutaneous contact with skin may range in severity from dermatitis to extensive chemical burns with coagulation necrosis.
- Toluene can affect skeletal muscles directly, resulting in rhabdomyolysis and myoglobinemia. Profound hypokalemia due to RTA can produce severe muscle weakness mimicking Guillain-Barré syndrome.