Reference summary — not medical advice or a personal risk estimate.
Shampoo
Liquid hair cleansers, including baby, dandruff, and colour-safe formulas.
Also known as: shampooing, hair wash, washing my hair
What this does NOT mean
Finding a factor documented in this product category does not establish that ordinary use of shampoo causes cancer. It means research — through regulatory testing, recall records, or IARC review — has found that chemical present in this category. Whether it matters for you depends on formulation, dose, frequency, and route of exposure.
What has been documented
- Coal-tar and coal-tar pitchIARC Group 1IARC Group 1Contains · high confidence
Ingredient in some medicated anti-dandruff and psoriasis shampoos.
Evidence source: US FDA
- FormaldehydeIARC Group 1IARC Group 1Byproduct of ingredients · high confidence
Released by preservatives like DMDM Hydantoin, Quaternium-15, Imidazolidinyl Urea.
Evidence source: EPA CPDat
How to read this page
A factor appearing on this page means it has been documented in this product category — through EPA / FDA testing, IARC monographs, or regulatory recall records. Whether it presents a meaningful personal risk depends on the specific formulation, dose, and how you're exposed. Click any factor to read what science actually says about it, and where.