Ideally, you want to aim for products with absolutely no bad ingredients. However, sometimes this is hard. If you happen to come across a product that contains Fragrance, and it is very low on the ingredients list, then it poses less of a threat to your hair. Therefore, you can choose to use this product if you have no other options. In contrast, if Fragrance is near the top of the ingredients list, then it is likely that the concentration is much higher and therefore the product should not be used. The same can be said for most other blacklist ingredients. It's also important to note that essential oils used as fragrances are generally considered safe, although some people may have sensitivities to certain ones.