HerbalEGram: Volume 5, Number 2, February 2008

Germany’s Federal Institute for Risk Assessment (BfR) announced in late December of 2007 that consumer exposure to coumarin through cosmetic products may be too high.¹ The BfR has already warned consumers against ingesting high levels of coumarin—particularly through high consumption of cassia cinnamon (Cinnamomum aromaticum)—following a health reassessment conducted in 2006.^1,2

Coumarin is a naturally-occurring secondary plant chemical found in such plants as sweet woodruff (Galium odoratum; syn. Asperula odorata), dates (Phoenix dactylifera), tonka bean (Dipteryx odorata), and especially in types of cinnamon such as cassia.* Coumarin has been shown to damage the liver of particularly sensitive individuals, although such damage was found to be reversible by halting coumarin intake. Based on hepatotoxicity, a tolerable daily intake (TDI) was established of 0.1 mg coumarin per kg bodyweight. A maximum of 2 mg coumarin per kg food may be added to foods as a flavoring, according to an EC Directive as well as the German Regulation on Flavorings.^1,2

Coumarin is also used as a synthetically-produced fragrance in perfumes, shower, gels, lotions, and deodorants.¹ BfR recently compiled data in an attempt to assess consumer exposure to coumarin through cosmetic products and found that consumers could significantly exceed the TDI for coumarin by using certain cosmetics. The agency stated that it has not yet been fully elucidated whether coumarin intake via the skin would have a similarly harmful effect on the liver as ingested coumarin, but it will assume on precautionary grounds that the hepatotoxic effects are similar until the question has been fully answered.

BfR has therefore stated that no coumarin should be used in cosmetic products for infants and toddlers. It further recommended that coumarin exposure of all consumers be reduced, including that provided by cosmetics. BfR called on cosmetic manufacturers to provide necessary data for further analyzing the coumarin content of cosmetics.

The International Fragrance Association (IFRA), an industry trade association, released its own statement in January, claiming that coumarin has been used in perfumery since the 19^th century and is an important ingredient for many fragrances.³ IFRA further argued that BfR’s precautionary approach may be too conservative and dismissive of new scientific data. According to the IFRA statement: “The potential hepatotoxic effects linked to oral intake (from extremely high doses, not necessarily representing amounts taken up via a normal diet) cannot simply be extrapolated to exposure resulting from dermal application of the material via cosmetic products. Furthermore, the fragrance industry is not aware of any systemic adverse health effects reported with regard to dermally applied coumarin.”³

According to IFRA, the fragrance industry, via its Research Institute for Fragrance Materials, has begun communication with the BfR to ensure that all existing safety-related information on coumarin is available to the agency.

Likewise, the German Cosmetics, Toiletry, Perfumery and Detergent Association (IKW) has released a statement arguing that coumarin-containing products on the market do not pose a threat to consumers.⁴ According to the statement, “The maximum levels of coumarin in certain product categories assumed by BfR in its consideration constitute very rare exceptional cases. In the vast majority of products the coumarin level is far lower—normally by a few orders of magnitude. In cosmetics which contain significant amounts of coumarin (more than 100 ppm in products which are rinsed off or more than 10 ppm in products which remain on the skin), this substance also appears separately in the list of ingredients.” [This refers to labeling in Europe, not the United States.] IKW noted that products for infants and babies, in particular, typically contain scarcely any coumarin at all.

IKW further argued that the TDI for ingested coumarin may be out of date, as more recent stystematic toxicological assessments of coumarin have assumed a “far higher safe value.” Further, the organization claims that there are robust scientific data suggesting that the hepatotoxic effects of coumarin from oral intake would not be expected from intake through the skin.

—Courtney Cavaliere

*Although cassia cinnamon contains relatively high levels of coumarin, Ceylon (or “true”) cinnamon (Cinnamomum verum) contains a low amount of coumarin, which the BfR considers safe for higher consumption by consumers. In a recent study (currently in press), a researcher applied a stable isotope dilution assay to several plants, foods, and essential oils and found high coumarin contents in cassia products and foods with cassia as an ingredient. The coumarin content of Ceylon cinnamion powder and bark essential oil was found to be much lower, with concentrations of about 3 orders of magnitude below those of respective cassia products. Cassia cinnamon sticks differ in appearance from Ceylon cinnamon sticks in that the bark is much thicker, but the BfR claims that it is almost impossible for consumers to distinguish between Ceylon and cassia cinnamon in cinnamon powder. [Refs: Selected Questions about Coumarin in Cinnamon and Other Foods. Federal Institute for Risk Assessment Web site. Available at: http://www.bfr.bund.de/cd/8487. Accessed: February 1, 2008. Rychlik M. Quantification of free coumarin and its liberation from glucosylated precursors by stable isotope dilution assays based on liquid chromatography-tandem mass spectrometric detection. Journal of Agricultural and Food Chemistry. (in press.)]

References