The IARC says you can enjoy your yoga class, but don’t breathe air (class 1 carcinogen), sit near a sun-filled window (class 1), apply aloe vera (class 2B) if you get a sunburn, drink wine or coffee (class 1 and class 2B), or eat grilled food (class 2A). And if you are a hairdresser or do shift work (both class 2A), you should seek a new career.”