What are carcinogens?

"In the natural world, mutations occur randomly and are typicall harmful to a cell." ("McGraw-Hill Ryerson Biology" 600) However, if the mutation is caused by a carcinogen which is, "... a cancer-causing agent (carcinos means "cancer"; gennan means "to produce")" (Hamilton, Whitney, and Sizer 324-348), then a cell will become cancerous which is harmful to the body. In the case of carcinogens, the mutation in the DNA occurs in the gene for mitosis.

Above is the hazard symbol for carcinogenic chemicals in the Globally Harmonized System.