Trimethylbenzenepropanol is a synthetic fragrance material that mimics the fresh floral scent of lily of the valley, also known in perfumery as muguet.

Why use synthetic lily of the valley?

Encapsulating the scent of lilies of the valley has been a perfumer’s dream for centuries, but nothing works. We now know that the delicate white bells don’t store essential oils – they release chemical substances that transform into fragrance upon contact with air.

You can’t always get what you want, but if you try sometimes you just might find daring scientists. Once they discovered the possibility of creating synthetic aroma molecules, many tried to replicate the scent of lily of the valley. This resulted in many versions, each with its own subtlety, including hydroxycitronellal, patented in the early 20th century; lilial and lyral in the mid-century; and trimethylbenzenepropanol in 1985.

Safety and regulations

Trimethylbenzenepropanol is on the European Union (EU) list of allergens that cosmetic companies must declare. Since 2009, EU cosmetics regulations, alongside other global bodies, have identified 26 materials (now 24 after lilial and lyral’s permanent ban) commonly found in fragrances that are more likely to cause allergic reactions in the form of skin sensitisation or irritation in susceptible individuals. These substances are referred to as allergens and are subject to restrictions to ensure their safe use in cosmetics. They must also appear on product labels when they occur above a certain limit: 0,001 % for leave-on products like moisturisers and 0,01 % for rinse-off products like shower gels. This list has been updated with 56 additional substances, which should start to appear on labels in 2026, with a deadline of 2028.

While allergies affect only a small minority, it is still important to highlight the presence of allergens in products so that customers who may be more sensitive to them can make informed decisions. Being an allergen doesn’t mean an ingredient is unsafe.

At Lush, these substances can occur naturally in essential oils, absolutes, and resinoids, or may be added to support our fragrance formulas. To help customers better understand what's in their products, we've colour-coded our ingredients on the labels. When obtained from natural sources, the allergen is in green text. When naturally occurring in an ingredient such as an essential oil, it is also listed in green, preceded by an asterisk (e.g. *Limonene). When added to a formula in a synthetic form, it is listed in black, without an asterisk, like Trimethylbenzenepropanol.

More on Lush and label regulations in this article.