Gasoline vapours can cause central nervous system (CNS) depression. No significant effects except eye and throat irritation were seen in volunteers exposed for 30 minutes to concentrations as high as 1054 parts per million or ppm, or for 8 hours to concentrations around 150-270 ppm. Mild dizziness was experienced by volunteers exposed for 1 hour to 2600 ppm. Pronounced dizziness was experienced by volunteers after about 5 minutes exposure to about 1100 ppm. Other CNS effects such as headache, lack of appetite, drowsiness and incoordination can occur. In one case, exposure for a few minutes to very high concentrations (above 5000 ppm) of aviation gasoline caused unconsciousness, pulmonary edema (a life-threatening accumulation of fluid in the lungs) and death.

When gasoline is NOT trapped against the skin and can freely evaporate, it is probably only mildly irritating or not irritating. However, case reports indicate that when gasoline is trapped against the skin (clothing is soaked in gasoline, skin is in contact with a puddle) for a long period (probably more than 30 minutes), serious burns and skin loss may occur. Absorption through the skin occurs, but is normally not significant.

Irritation reported by volunteers exposed to vapour concentrations as low as 164 ppm for 30 minutes. The liquid may cause temporary pain if splashed in the eye(s), but probably does not cause permanent damage. No significant irritation was observed in studies with rabbits.

Gasoline is moderately toxic if ingested. It may cause burning in the mouth, throat and chest as well as stomach irritation, nausea, vomiting and cyanosis (bluish discoloration of the fingertips, toes, lips and other extremities). Central nervous symptom depression, such as unconsciousness and coma, can occur. Inhalation of gasoline into the lungs (aspiration) can occur while gasoline is in the mouth, being swallowed or during vomiting. Aspiration often occurs when gasoline is siphoned by mouth. The aspiration of even a small amount (less than an ounce) of gasoline into the lungs is very hazardous and may cause death. Aspirated gasoline can cause chemical pneumonitis (inflammation of the lungs) and/or pulmonary edema (a life-threatening accumulation of fluid in the lungs).

EFFECTS ON THE SKIN: Repeated or prolonged contact can dry the skin (removes fat from skin) and cause cracking, irritation and dermatitis. Allergic reactions (hypersensitivity) have been reported but these are rare occurrences.

EFFECTS ON THE BLOOD: There are reports of effects on the blood in gasoline tanker crewmen and painters who were exposed to gasoline. These workers were probably exposed to other chemicals and therefore it is not possible to establish a causal relationship. However, benzene is known to cause harmful effects on the blood and may be present in gasoline in small amounts.

EFFECTS ON THE PERIPHERAL NERVOUS SYSTEM: Gasoline is composed of different paraffins (alkanes) such as n-hexane. Prolonged and/or repeated exposure to n-hexane can cause irreversible damage to the peripheral nervous system. Whether or not exposure to gasoline can cause this effect depends on the presence of n-hexane and its concentration and on the degree and duration of exposure.

EFFECTS ON THE NEUROLOGICAL SYSTEM: Abuse of gasoline by inhalation of the vapours by so-called "sniffers" has resulted in many neurological effects. Dizziness, tremor, visual and auditory hallucinations, and loss of memory were symptoms reported in case studies of abusers who sniffed vapours sometimes daily for years. These situations are not relevant to occupational exposures.

Effects on memory, intellectual capacity, psychomotor and learning ability were seen in attendants exposed to gasoline vapours at gas stations. The most significant effects were seen in attendants exposed for more than 5 years. Very little effect was seen in attendants with less than 1 year of exposure. The exposure concentrations were not cited in the study. Therefore, it is difficult to evaluate the results.

The available human information is inadequate for evaluation because there is no detailed data concerning actual exposure to gasoline. Unleaded gasoline caused kidney cancers in male rats and liver cancers in female mice. The International Agency for Research on Cancer (IARC) concludes that gasoline is possibly a human carcinogen (Group 2B). Gasoline may contain known carcinogens (e.g., benzene, ethylene dibromide).

No information suitable for evaluation. There is a Russian study of women exposed to gasoline above the maximum permissible level which described effects on menstrual cycle, and childbearing and lactation functions were observed. Also, a number of newborns were malformed. The actual exposure concentration and the length of exposure were not cited and so this study is not suitable for evaluation.

No human information available. No effect seen in one rat study.

Methyl ethyl ketone or methyl isobutyl ketone enhance the action of n-hexane. n-Hexane is one type of paraffin (alkane) found in gasoline.

Inadequate information for evaluation.