Synonyms: Trichloromethane
trichloroform
freon 20
COBEHN Spray-Cleaner solvent
formyl trichloride
methane trichloride
methenyl trichloride
methyl trichloride
2. Effects on Humans: The toxicity of chloroform is well understood because of its long history of use as an anesthetic. Inhalation of 10,000 ppm of chloroform vapor produces clinical anesthesia. Inhalation of higher doses causes cardiovascular depression, with death resulting from ventricular fibrillation. Delayed death is associated with liver necrosis [ACGIH 1991]. Chronic inhalation of chloroform may cause psychiatric and neurological symptoms, including depression, hallucinations, and moodiness [NLM 1995]. In studies with human volunteers, exposure to 4,100 ppm causes serious disorientation, and 1,000 ppm caused dizziness, nausea, and after effects of fatigue and headache. Exposures of 20 to 70 ppm for undefined lengths of time caused less extreme, but still evident, effects on the central nervous system [Hathaway et al. 1991]. Liver enlargement was demonstrated in 17 of 68 workers exposed to chloroform at concentrations of 10 to 200 ppm for 1 to 4 years. Among other factors that increase the toxic effects of chloroform is ethanol [Hathaway et al. 1991]. As a result, alcoholics react more severely to exposure [Genium 1992]. Exposure to high concentrations of chloroform vapor causes redness and twitching of the eyes. Liquid chloroform splashed into the eye causes immediate burning, pain, and possible injury to the cornea. The eye returns to normal in 1 to 3 days [Grant 1986]. Application of chloroform to the skin causes burning, pain, redness, and vesiculation. Based on experimental animal studies, IARC has concluded that chloroform should be regarded as a cancer risk to humans. One study of people exposed to chloroform in their drinking water showed a correlation between chloroform concentration and rectal and bladder cancer [Hathaway et al. 1991].
* Signs and symptoms of exposure
1. Acute exposure: Inhalation of chloroform causes signs and symptoms of central nervous system depression. In the initial stages, there is a feeling of warmth of the face and body, then irritation of the mucous membranes, eyes, and skin, followed by excitation, loss of reflexes, sensation, and consciousness. The pupils dilate and have a reduced reaction to light. Prolonged inhalation causes paralysis, cardiac and respiratory failure, and death [Sax and Lewis 1989; Genium 1992]. Other symptoms may include digestive upset, mental dullness, and dizziness [Sittig 1991]. Chloroform vapors may irritate the eyes and skin. Chloroform liquid causes burning of the eye and transient corneal injury. Skin exposure results in burning and redness [NLM 1995]. Exposure of pregnant women to chloroform may result in fetal death or malformation based on animals studies [Clayton and Clayton 1982].
