What is IARC Group 2B?
Group 2B — possibly carcinogenic. 217 factors in the Meyron reference are currently classified this way.
Plain-language explanation
Some evidence exists but it is limited or mixed. Less certain than Group 2A.
Examples
Pickled vegetables (traditional Asian)
Eaten. Traditional Asian-style pickled vegetables prepared with high salt and fermentation, where they are dietary staples (parts of East and Southeast Asia).
-Methylstyrene
Breathed and on skin. Industrial solvent — occupational exposure in cleaning, degreasing, and chemical manufacturing.
1-[(5-Nitrofurfurylidene)amino]-2-imidazolidinone
Mostly occupational. Industrial chemical handled in manufacturing or research; the general public rarely encounters meaningful amounts.
1-Amino-2,4-dibromoanthraquinone
Mostly industrial — used as a dye in textiles, leather, paper, or research. Some are or were used in cosmetics or food colouring; check the specific entry.
1-Bromopropane
Mostly occupational. Industrial chemical handled in manufacturing or research; the general public rarely encounters meaningful amounts.
1-Chloro-2-methylpropene
Mostly occupational. Industrial chemical handled in manufacturing or research; the general public rarely encounters meaningful amounts.
1-Hydroxyanthraquinone
Mostly industrial — used as a dye in textiles, leather, paper, or research. Some are or were used in cosmetics or food colouring; check the specific entry.
1,1-Dimethylhydrazine
Mostly occupational. Industrial chemical handled in manufacturing or research; the general public rarely encounters meaningful amounts.
1,2-Dibromo-3-chloropropane
Breathed and on skin. Industrial solvent — occupational exposure in cleaning, degreasing, and chemical manufacturing.
1,2-Dichloroethane
Breathed and on skin. Industrial solvent — occupational exposure in cleaning, degreasing, and chemical manufacturing.
Reading IARC classifications carefully
The IARC groups describe the strength of evidence that an agent can cause cancer under some conditions — not the size of the risk to any individual, not the dose required, and not how likely exposure is in everyday life. A Group 1 classification does not mean an exposure is unavoidable or catastrophic; a Group 3 classification does not mean it is safe.