CHAPTER 2-80: HYDROCARBONS

INTRODUCTION

Hydrocarbons are used widely as solvents, degreasers, fuels, and lubricants. Besides inadvertent exposure, poisoning also commonly occurs from inhalation of volatile hydrocarbon gases used as drugs of abuse. Hydrocarbons include organic compounds derived from petroleum distillation as well as many other sources, including plant oils, animal fats, and coal. Subcategories of hydrocarbons include aliphatic (saturated carbon structure), aromatic (containing one or more benzene rings), halogenated (containing chlorine, bromine, or fluorine atoms), alcohols and glycols, ethers, ketones, carboxylic acids, and many others. This chapter emphasizes toxicity caused by common household hydrocarbons. See specific chemicals elsewhere in Section II and in Table IV–4.

MECHANISM OF TOXICITY

Hydrocarbons may cause direct injury to the lung after pulmonary aspiration or systemic intoxication after ingestion, inhalation, or skin absorption (Table II–34). Many hydrocarbons are also irritating to the eyes and skin.

1. Pulmonary aspiration. Chemical pneumonitis is caused by direct tissue damage and disruption of surfactant. Aspiration risk is greatest for hydrocarbons with low viscosity and low surface tension (eg, petroleum naphtha, gasoline, turpentine).

2. Ingestion

   1. Aliphatic hydrocarbons and simple petroleum distillates such as lighter fluid, kerosene, furniture polish, and gasoline are poorly absorbed from the GI tract and do not pose a significant risk for systemic toxicity after ingestion as long as they are not aspirated.

   2. In contrast, many aromatic and halogenated hydrocarbons, alcohols, ethers, ketones, and other substituted or complex hydrocarbons are capable of causing serious systemic toxicity, such as coma, seizures, and cardiac dysrhythmias.

3. Inhalation of hydrocarbon vapors in an enclosed space may cause intoxication as a result of systemic absorption or displacement of oxygen from the atmosphere; in addition, sensitization of the myocardium to catecholamines can cause cardiac dysrhythmias.

4. Injection of hydrocarbons into skin, subcutaneous tissue, or muscle may cause a severe local inflammatory reaction and liquefaction necrosis.

5. Skin and eye contact can cause local irritation. Dermal absorption can be significant for some agents but is insignificant for most of the simple aliphatic compounds.

TOXIC DOSE

The toxic dose is variable, depending on the agent involved and whether it is aspirated, ingested, injected, or inhaled.

1. Pulmonary aspiration...