Coumarin and Tonka Beans Safety and Legality

Background:

Coumarin is a natural substance with a “sweet hay” aroma, found in bison grass (sweetgrass), tonka beans, sweet woodruff, meadowsweet,  cassia cinnamon, cherry blossom tree leaves, and it is used in tobacco and perfumes. Bison grass vodka (zubrowka) derives its flavor primarily from the coumarin in the grass.

In the United States, tonka beans are expressly forbidden as a food additive by the FDA, as is any direct addition of coumarin. Tonka beans are legal to use in some other countries. 

Legal Regulations:

Tonka beans are expressly forbidden to use in food in the US, as is coumarin as a direct additive.  According to the US FDA:

"Coumarin - SY/FS, BAN, Any food containing coumarin added as such or as a constituent of tonka beans or tonka extract is adulterated." [link]

SY = synthetic FS = Substances permitted as optional ingredient in a standardized food BAN = Substances banned prior to the Food Additives Amendment (FAA) because of toxicity. 

Sweet Woodruff is allowed in alcoholic beverages only [link]. In "may wine," sweet woodruff may be used with a limit of 5ppm coumarin [link to spreadsheet] in the United States. 

Alcoholic beverages sold in the European Union are limited to a maximum of 10 mg/l coumarin by law. [link] [link] [link]

The 2004 tolerable daily food intake (TDI) set by the European Food Safety Authority (EFSA) at 0.1mg/kg daily. For a fully grown adult to research this threshold, they would need to consume about 2400 plates of tonka bean flavoured desserts. [link] 

Canada: According to this article [link] "In Canada, directly adding coumarin to food is illegal, but consuming it through other spices, like tonka beans, is not. " Provinces may have different laws from each other, but according to the Liquor Control Board of Ontario [link] the maximum amount of coumarin in "bison grass products" in Ontario is 100 µg/L which is .1 ppm. 

Coumarin vs Coumadin Confusion

Coumadin is a prescription medicine sold as Wafarin, and is a blood thinning agent. It is affected by grapefruit, leafy greens, basil, and green teas so people taking it should be aware.

Coumarin is used to make coumadin, but coumarin is not anti-coagulant itself.

Safety Information:

Coumarin is moderately toxic to the liver and kidneys. [link] 

"One of the most common ways that coumarin makes its way into our diets is actually through [cassia, not Ceylon] cinnamon" [link]

The 2004 tolerable daily food intake (TDI) set by the European Food Safety Authority (EFSA) at 0.1mg/kg daily. For a fully grown adult to research this threshold, they would need to consume about 2400 plates of tonka bean flavoured desserts. [link] 

Further Reading:

"Coumarin, the illegal chemical causing Americans to miss out on a sweet treat." McGill [link]