Health Hazard Information

Acute Effects:

• Acute inhalation exposure of humans caused changes in breathing and some chest pains during an accidental release of carbon disulfide. (1)
• Nausea, vomiting, dizziness, fatigue, headache, mood changes, lethargy, blurred vision, delirium, and convulsions have also been reported in humans acutely exposed by inhalation. (3)
• Brain chemistry changes and sensory and motor nerve conduction alterations were observed in rats acutely exposed to carbon disulfide by inhalation. (1)
• Animal studies show transitory effects associated with the target organ toxicity (central nervous system (CNS), blood, liver, eyes) seen from chronic exposure. (1)
• Tests involving acute exposure of rats, mice, and rabbits have shown carbon disulfide to have low acute toxicity from inhalation and moderate acute toxicity by ingestion. (4)

Chronic Effects (Noncancer):

• Neurotoxic effects have been observed in chronic human and animal inhalation studies.  Behavioral and neurophysiological changes, reduced nerve conduction velocity, peripheral neuropathy, and polyneuropathy have been observed in chronically exposed workers. (1,2,5)
• An increased incidence of coronary heart disease has been observed in an epidemiological study of workers who chronically inhaled carbon disulfide in the workplace.  Concomitant exposure to other chemicals and a failure to control for other coronary heart disease risk factors have been noted with this study.  An increased incidence of angina has been reported in another occupational study. (1,2)
• Muscle pain, headaches, and general fatigue have been reported by workers chronically exposed to carbon disulfide in the air. (1,3)
• Ocular effects have been observed in chronically exposed workers. (1)
• Workers who handled fibers made from a polymer solution in carbon disulfide developed blisters and eczematous lesions on their hands. (1,3)
• Chronic inhalation exposure has been observed to affect the CNS, blood, liver, and kidneys in animals. (1)
• The Reference Concentration (RfC) for carbon disulfide is 0.7 milligrams per cubic meter (mg/m³) based on neurological effects in humans. The RfC is an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious noncancer effects during a lifetime.  It is not a direct estimator of risk but rather a reference point to gauge the potential effects.  At exposures increasingly greater than the RfC, the potential for adverse health effects increases.  Lifetime exposure above the RfC does not imply that an adverse health effect would necessarily occur. (5)
• EPA has medium confidence in the study on which the RfC was based because it is well designed and conducted, uses adequate numbers of subjects, and is well supported by other occupational studies examining the same effect; however, considerable uncertainty exists regarding the exposure histories of the cohorts examined; medium confidence in the database because a considerable number of well-conducted occupational  studies have defined the effects of carbon disulfide in humans; however, a significant question remains regarding the possibility of developmental  effects in humans; and consequently medium confidence in the RfC. (5)
• The Reference Dose (RfD) for carbon disulfide is 0.1 milligrams per kilogram body weight per day (mg/kg/d) based on fetal toxicity/malformations in rabbits. (5)
• EPA has medium confidence in the study on which the RfD was based because this study was a well-designed multispecies study that provided adequate toxicologic endpoints; medium confidence in the database because it contains supportive reproductive and epidemiologic studies; and, consequently, medium confidence in the RfD. (5)

Reproductive/Developmental Effects:

• Reproductive effects, such as decreased sperm count and decreased libido in men and menstrual disturbances in women, have been reported from occupational settings involving inhalation exposure to carbon disulfide. (1-3)
• Developmental effects, including skeletal and visceral malformations, embryotoxicity, and functional and behavioral disturbances, have been observed in several animal studies across a wide exposure range. (2)
• Pharmacokinetic studies indicate that carbon disulfide and its metabolites cross the placenta and localize in the target organs of the fetus (brain, blood, liver, and eyes). (1)

Cancer Risk:

• In a study of workers exposed by inhalation to carbon disulfide and other solvents, an increased incidence of lymphatic leukemia was reported.  However, there were many confounding factors in this study, making it difficult to interpret the results. (1,2)
• EPA has not classified carbon disulfide for human carcinogenicity. (5)