intermediate definition an intermediate is a substance formed during a middle step of a chemical reaction between reactants and the desired product
The international pictogram for chemicals that are sensitising, mutagenic, carcinogenic or toxic to reproduction. A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke.
Cancer is caused by changes in a cellâs DNA â its genetic âblueprint.â Some of these changes may be inherited from our parents. Others may be caused by outside exposures, which are often referred to as environmental factors. Substances and exposures that can lead to cancer are called carcinogens. Some carcinogens do not affect DNA directly, but lead to cancer in other ways. For example, they may cause cells to divide at a faster than normal rate, which could increase the chances that DNA changes will occur.