Exposure can also irritate the nose and throat. High exposures to benzene may cause irregularities in the heart beat which can lead to death. Repeated exposure can damage the bone marrow, which is the blood-forming organ, causing a condition called aplastic anaemia. This may also lead to death. There is sufficient evidence that benzene causes leukaemia in exposed workers.
Many scientists say that there is no safe level of exposure to a carcinogen.
Benzene may cause birth defects in animals. Until further testing has been done it should be handled very carefully as a possible agent causing birth defects in humans as well. In several countries there are severe restrictions for using and selling benzene. As a solvent benzene can be substituted with a variety of less hazardous ones. Toluene is a similar solvent to benzene.