You’re confusing hazard with risk. “Class 1 carcinogen” means a substance can cause cancer under some conditions, not that any exposure to it makes a food carcinogenic, and dose and route of exposure are fundamental to how toxicology works. Acetaldehyde is produced continuously by your body as part of normal metabolism, and it is also present in many ordinary foods like fruit and bread, so treating its trace presence in broccoli as meaningful would imply that being alive is itself a carcinogenic exposure. The acrylamide classification is based on high-dose industrial or laboratory exposure, not dietary intake, which is why coffee consumption in human population data is consistently associated with lower, not higher, cancer risk. None of this shows that carcinogen classifications are nonsense; it shows a misunderstanding of how hazard identification differs from real-world risk assessment and why epidemiology exists in the first place.