Coumarin

Coumarin is moderately toxic to the liver and kidneys, with a "Median Lethal Dose" (<a href="http://en.wikipedia.org/wiki/Median_lethal_dose" title="Median lethal dose" >LD50</a>) of 275 mg/kg — low compared to related compounds.

Although only somewhat dangerous to humans, coumarin is a potent <a href="http://en.wikipedia.org/wiki/Rodenticide" title="Rodenticide" >rodenticide</a>: Rats and other rodents metabolize it largely to 3,4-coumarin epoxide, a toxic compound that can cause <a href="http://en.wikipedia.org/wiki/Internal_hemorrhage" title="Internal hemorrhage" class="mw-redirect" >internal hemorrhage</a> and death.

Humans metabolize it largely to <a href="http://en.wikipedia.org/wiki/7-hydroxycoumarin" title="7-hydroxycoumarin" class="mw-redirect" >7-hydroxycoumarin</a>, a compound of lower toxicity. The German Federal Institute for Risk Assessment has established a "tolerable daily intake" (TDI) of 0.1 mg coumarin per kg body weight, but also advises, [if] this level is exceeded for a short time only, there is no threat to health.<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-bfrtdi-15" >[16]</a> For example, a person weighing 60 kg (about 132 lbs) would have a TDI of approximately 6.0 mg of coumarin. The U.S. <a href="http://en.wikipedia.org/wiki/Occupational_Safety_and_Health_Administration" title="Occupational Safety and Health Administration" >Occupational Safety and Health Administration</a> (OSHA) regards Coumarin to be not classifiable as to its carcinogenicity to humans.<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-16" >[17]</a>

European health agencies have warned against consuming high amounts of <a href="http://en.wikipedia.org/wiki/Cinnamomum_aromaticum" title="Cinnamomum aromaticum" >cassia</a> bark, one of the four species of <a href="http://en.wikipedia.org/wiki/Cinnamon" title="Cinnamon" >cinnamon</a>, because of its coumarin content.[<a href="http://en.wikipedia.org/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability" >not in citation given</a>]<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-17" >[18]</a>

According to the German Federal Institute for Risk Assessment (BFR), 1 kg of (cassia) <a href="http://en.wikipedia.org/wiki/Cinnamon" title="Cinnamon" >cinnamon</a> powder contains approximately 2.1 to 4.4 g of coumarin.<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-bfr.bund.de-18" >[19]</a> Powdered Cassia Cinnamon weighs 0.56 g/cc;<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-19" >[20]</a> therefore, 1 kg of Cassia Cinnamon powder is equal to 362.29 teaspoons (1000 g divided by 0.56 g/cc multiplied by 0.20288 tsp/cc). This means 1 teaspoon of cinnamon powder contains 5.8 to 12.1 mg of coumarin, which may be above the Tolerable Daily Intake for smaller individuals.<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-bfr.bund.de-18" >[19]</a>However, it is important to note that the BFR only cautions against high daily intakes of foods containing coumarin. Its report<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-bfr.bund.de-18" >[19]</a> specifically states that "Ceylon" cinnamon,<a href="http://en.wikipedia.org/wiki/Cinnamomum_verum" title="Cinnamomum verum" >Cinnamomum verum</a>, contains 'hardly any' coumarin.

<a href="http://en.wikipedia.org/wiki/Chamomile" title="Chamomile" >Chamomile</a>, a common herbal tea, also contains coumarin.

Coumarin is often found in <a href="http://en.wikipedia.org/wiki/Tobacco" title="Tobacco" >tobacco</a> products and artificial <a href="http://en.wikipedia.org/wiki/Vanilla" title="Vanilla" >vanilla</a> substitutes, despite having been banned as a food additive in numerous countries since the mid-20th century.

Coumarin was banned as a food additive in the United States in 1954, largely because of <a href="http://en.wikipedia.org/wiki/Hepatotoxicity" title="Hepatotoxicity" >hepatotoxicity</a> results in rodents.<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-20" >[21]</a> The U.S. OSHA considers this compound to be only a lung-specific carcinogen,[<a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" >citation needed</a>] and "not classifiable as to its carcinogenicity to humans".<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-21" >[22]</a>

Coumarin was banned as an adulterant in cigarettes by tobacco companies in 1997, but due to the lack of reporting requirements to the US <a href="http://en.wikipedia.org/wiki/Department_of_Health_and_Human_Services" title="Department of Health and Human Services" class="mw-redirect" >Department of Health and Human Services</a> it was still being used as a flavoring additive in pipe tobacco.[<a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" >citation needed</a>]

Coumarin is currently listed by the United States <a href="http://en.wikipedia.org/wiki/Food_and_Drug_Administration" title="Food and Drug Administration" >Food and Drug Administration</a> (FDA) among "Substances Generally Prohibited From Direct Addition or Use as Human Food", according to 21 <a href="http://en.wikipedia.org/wiki/Code_of_Federal_Regulations" title="Code of Federal Regulations" >CFR</a> 189.130,<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-22" >[23]</a><a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-23" >[24]</a> but some natural additives containing coumarin, such as <a href="http://en.wikipedia.org/wiki/Sweet_woodruff" title="Sweet woodruff" class="mw-redirect" >sweet woodruff</a> (Galium odoratum) due to its coumarin odor, are allowed "in alcoholic beverages only" (21 <a href="http://en.wikipedia.org/wiki/Code_of_Federal_Regulations" title="Code of Federal Regulations" >CFR</a> 172.510).<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-24" >[25]</a>

In Europe, such beverages are very popular, for example <a href="http://en.wikipedia.org/wiki/Maiwein" title="Maiwein" class="mw-redirect" >Maiwein</a> (white wine with woodruff) and <a href="http://en.wikipedia.org/wiki/%C5%BBubr%C3%B3wka" title="Żubrówka" >Żubrówka</a> (vodka flavoured with bison grass). However, the coumarin content of these drinks is said to cause headaches.

Coumarin is subject to restrictions on its use in perfumery <a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-25" >[26]</a> as some people may become sensitised to it, however the evidence that coumarin can cause an allergic reaction in humans is disputed.<a href="http://en.wikipedia.org/wiki/Coumarin#cite_note-26" >[27]</a>