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.
Areas of research. Cause. Early research on the cause of cancer was summarized by Haddow in 1958. The first chemical carcinogen was identified in 1928-29 as 1:2-5:6-dibenzanthracene, and the carcinogeneic substance in pitch was identified as 3:4-benzopyrene in 1933.