What is it?
An essential oil steam-distilled from the bark of young shoots of the Ceylon cinnamon tree, Cinnamomum verum, which labels list under its synonym Cinnamomum zeylanicum. It is mostly cinnamaldehyde, the compound behind cinnamon’s warm, spicy smell and taste, with smaller amounts of eugenol, beta-caryophyllene and linalool. It is used in small amounts in fragrances, oral care products and flavorings.
Key information
- Cinnamon bark oil is roughly two-thirds cinnamaldehyde (cinnamal), one of the fragrance chemicals most often reported to cause skin allergy.
- IFRA limits cinnamaldehyde to under 0.5 percent in nearly all product categories, and to as little as 0.014 percent in some.
- The European Food Safety Authority considers the oil irritating to skin and eyes and a skin sensitizer.
- EU labels must name cinnamon bark oil above 0.001 percent in leave-on or 0.01 percent in rinse-off products placed on the market after July 31, 2026.
More information
Five batches analyzed for the European Food Safety Authority (EFSA) contained 65 to 71 percent cinnamaldehyde and about 6 percent eugenol, another established skin allergen. They also contained 0.12 to 0.34 percent safrole, which causes liver tumors in rodents. Because of that safrole, the neat oil is classified as a category 1B carcinogen under EU chemical rules; a finished cosmetic contains far less.
The bigger issue is skin allergy. In its 2012 review, the EU’s Scientific Committee on Consumer Safety (SCCS) classed cinnamon bark oil as an established contact allergen because of its allergenic constituents, and placed cinnamal among a dozen fragrance chemicals of special concern, each linked to more than 100 reported cases. In one North American study, 3.1 percent of 4,435 patients reacted to cinnamal. Cinnamal can also cause contact urticaria, a hive-like reaction, and EFSA, which concludes the oil irritates skin and eyes and is a skin sensitizer, notes reports of mouth and lip inflammation from cinnamaldehyde in toothpaste and breath fresheners.
IFRA restricts cinnamaldehyde because of skin sensitization and systemic toxicity, keeping it below 0.5 percent in nearly every product category and as low as 0.014 percent in some. Cinnamal is one of the 26 fragrance allergens the EU already requires to be named on labels, and products placed on the EU market after July 31, 2026, must also name cinnamon bark oil itself above 0.001 percent in leave-on or 0.01 percent in rinse-off products.
Reality check: cinnamon in food and cinnamon bark oil on skin are different exposures. The oil is permitted at the very low levels IFRA allows, but its main constituent is a leading fragrance allergen. If you have a fragrance allergy or react to cinnamon-flavored products, check labels for Cinnamomum Zeylanicum Bark Oil and cinnamal. Never put the undiluted oil on skin.
Sources: SCCS: Opinion on fragrance allergens in cosmetic products (2012); IFRA: Standard for cinnamic aldehyde (Amendment 49); EFSA Journal (2022): Safety and efficacy of feed additives consisting of cinnamon bark oil and cinnamon leaf oil; Official Journal of the EU: Commission Regulation (EU) 2023/1545 on labelling of fragrance allergens
