Studies evaluating inhalation exposure have demonstrated that styrene is a strong irritant. Eye, nose and throat irritation is common at exposure levels above 50 to 100 ppm but can also occur at levels of about 20 to 30 ppm. At very high levels chronic bronchitis type symptoms and other respiratory symptoms appear. Multiple central and peripheral acute nervous system effects have been described at levels of about 100 ppm but some neurological symptoms and color vision impairment may also appear at much lower levels. Effects on the liver (acute in animals, chronic in exposed workers), and the kidney and also genotoxic effects have been described at low levels.In the past, the so called "styrene sickness" was described in workers heavily exposed to styrene including nausea and vomiting, loss of appetite, and general weakness.