Group 1 carcinogens are substances classified as having sufficient evidence to be considered carcinogenic to humans, according to the International Agency for Research on Cancer (IARC). This classification is part of a four-tier system that evaluates the carcinogenic risk of chemicals, mixtures, occupational exposures, and lifestyle factors. Group 1 includes well-known carcinogens such as tobacco smoke, asbestos, and ultraviolet radiation.
