Vinyl chloride has little acute toxicity, and air levels over 8000 ppm may be tolerated for 5 minutes without the development of symptoms. Longer exposures have been associated with headache, dizziness, euphoria, ataxia, and narcosis. Cardiac, circulatory, and respiratory irregularities have also been noted with acute exposures. Acute, high-level exposures have resulted in death, presumably due to narcosis.

Chronic occupational exposures to vinyl chloride at levels of several hundred ppm have led, in the past, to vinyl chloride disease, a condition involving a number of organ systems and tissues and resulting in a variety of clinical symptoms. The reported period of exposure before the onset of this disease ranged from 1 month to 3 years. New cases of vinyl chloride disease have not been reported since 1974, when permissible workplace exposure levels were reduced to 1 ppm.

The signs of vinyl chloride disease included a scleroderma-like condition of the connective tissue of the fingers, accompanied by thickening of the dermis. Acro-osteolysis, a rare bone disease resulting in decalcification of the terminal phalanges of the hand, was also seen. Acro-osteolysis was frequently preceded by a Raynaud-type phenomenon in which there was reversible constriction of the arterioles, leading to numbness, pallor, and cyanosis of the fingers.

The onset of vinyl chloride-induced liver disease (malignant or nonmalignant) can be insidious, with a clinical picture of nonspecific hepatic injury. Abdominal pain, followed by weakness, fatigue, and weight loss are the most common symptoms. Fibrosis and cirrhosis may develop, resulting in hepatomegaly, splenomegaly, portal hypertension, thrombocytopenia, and esophageal varices. These pathologic effects may occur singly or in any combination and may be accompanied by other less characteristic signs, such as hematologic changes and pulmonary effects.