Carcinogens are graded. The International Agency for Research on Cancer (IARC) from the World Health Organization (WHO) has published a very authoritative list of carcinogens with their grades.

The specific grades are as follows:

Group 1 carcinogens: carcinogens for which there is clear evidence that they cause cancer in humans

Group 2 carcinogens: carcinogens for which there is uncertain evidence that they cause cancer in humans

Group 3 carcinogens: carcinogens for which there is uncertain evidence that they cause cancer in both animals and humans

Group 1 carcinogens are represented by alcohol and alcoholic beverages, Cigarettes, Chinese salted fish, solar radiation, ultraviolet rays, tanning equipment in beauty salons, aflatoxin, betel nut, radon, in addition, indoor coal burning, rubber industry, wood shavings and so on are also included in the category 1 carcinogens. 2 carcinogens on behalf of the acrylamide, lead, coffee, red meat, gasoline and so on, this kind of carcinogens, cancer in humans has not been clearly proved, we pay attention to it. 3 carcinogens on behalf of the mercury, leather, leather processing, Sudan red, melamine and other carcinogenic substances. Processing, Sudan red, melamine, sulfur dioxide, hydrogen peroxide, hypochlorite, printing ink, ampicillin, polyethylene, polypropylene, polyvinyl chloride, fiberglass. Coal dust, rust, caffeine, cholesterol, static magnetic fields, tea, vitamin K. The evidence that this category of items causes cancer in both animals and people is inconclusive; in fact, the likelihood of this category causing cancer is very, very small.