Toxicology – Hydrocarbon Ingestion

Sources

Hydrocarbons are found in many fuels, solvents, and petroleum products. Examples include:

• Propane and butane
• Hexane and octane
• Gasoline
• Kerosene
• Motor oil

Typical Presentation

A person drinks a small amount of gasoline and immediately begins gagging and coughing. The main danger is often not absorption from the stomach, but aspiration into the lungs.

Clinical Features

Possible symptoms include:

• Coughing
• Gagging
• Vomiting
• Shortness of breath
• Hypoxia
• Altered mental status
• Syncope

Aspiration can cause:

• Chemical pneumonitis
• Pulmonary edema
• Respiratory distress

Inhalation of hydrocarbon vapors may also cause:

• CNS depression or intoxication
• Dizziness and impaired coordination
• Cardiac dysrhythmias

Repeated inhalational abuse can lead to chronic neurologic injury.

Mechanism of Action

Hydrocarbon toxicity depends greatly on the physical properties of the product.

Low-viscosity hydrocarbons spread easily and are more likely to enter the airway during swallowing or vomiting.

Once aspirated, they:

• Directly injure pulmonary tissue
• Disrupt surfactant
• Trigger inflammation and chemical pneumonitis

Some inhaled hydrocarbons can also sensitize the heart to catecholamines, increasing the risk of dangerous dysrhythmias.

Aspiration Risk

Aspiration risk is generally higher with low-viscosity hydrocarbons.

Examples:

• Gasoline and kerosene: relatively high aspiration risk
• Motor oil: lower aspiration risk because of higher viscosity

Management

Treatment is mainly supportive:

• Remove the patient from further exposure
• Support airway and breathing
• Provide supplemental oxygen if needed
• Monitor for respiratory deterioration

There is no specific antidote for hydrocarbon aspiration.

Inducing vomiting is avoided because it can increase the risk of aspiration. Activated charcoal is generally not useful for uncomplicated aliphatic hydrocarbon ingestion.

Key Points

• The major danger after ingestion is often aspiration, not systemic absorption.
• Low viscosity = higher aspiration risk.
• Chemical pneumonitis may develop after coughing or choking during ingestion.
• High-viscosity products such as motor oil usually pose less aspiration risk.
• Treatment is primarily supportive, with attention to respiratory symptoms and cardiac rhythm abnormalities.