Butylphenyl Methylpropional Worst Fragrance Synthetic and Natural No known benefits Butylphenyl Methylpropional at a glance Fragrance ingredient with a floral scent Proven to irritate skin May be a health risk if multiple products containing it are used Rarely used in skin care or makeup products Butylphenyl Methylpropional description Butylphenyl methylpropional is a synthetic fragrance ingredient with a strong floral scent. It also goes by the name 2-(4-tert-butylbenzyl) propionaldehyde or lilial. Butylphenyl methylpropional’s use in cosmetics is restricted due to concerns over sensitivity, especially if multiple products (both personal care and household items such as air freshener) are used routinely. This ingredient is banned for use in cosmetic and personal care products sold in European Union member countries due to potential reproductive harms in people. Worth noting is that this ingredient rarely shows up in skin care or makeup products, being more common as a fragrance additive in hair care products, perfumes and household cleansers. In countries where butylphenyl methylpropional is still permitted for use, it must be indicated on the ingredient list if the product contains more than 0.001% and is meant to be left on skin; it also must be listed if the product contains more than 0.01% and is meant to be rinsed. This would not apply to its usage in household cleaners and laundry products.