What is Rue, Oil?
Rue oil is an essential oil derived from Ruta graveolens L., commonly known as rue or herb-of-grace. The oil is obtained through extraction processes from the leaves and stems of this herbaceous plant native to southeastern Europe. The CAS number 8014-29-7 identifies this specific substance in chemical databases. Rue oil contains volatile compounds including methylnonylketone, 2-undecanone, and various terpenes that contribute to its characteristic bitter, pungent aroma and flavor profile.
Common Uses
Historically, rue has been used as a flavoring agent in certain alcoholic beverages, particularly in Mediterranean and Central European cuisines. The oil has been incorporated into liqueurs, bitters, and traditional herbal preparations. In food manufacturing contexts where it has been used, rue oil typically appears in very small quantities due to its intense flavor characteristics. However, commercial food use in the United States is limited due to regulatory restrictions and lack of FDA GRAS (Generally Recognized as Safe) status.
Safety Assessment
Rue contains compounds that have raised safety considerations in scientific literature. The plant and its oil contain furanocoumarins and other phototoxic compounds that can cause dermatological reactions upon skin contact combined with sun exposure. When ingested, rue has traditionally been associated with abortifacient properties, leading to warnings against consumption during pregnancy in historical medical texts.
The FDA has not established rue oil as GRAS for food use, which reflects the lack of sufficient safety data and potential concerns regarding its use as a food additive. According to FDA records, there are no reported adverse events associated with rue oil in foods, and no product recalls have been issued. However, the absence of reported adverse events may reflect limited commercial use rather than established safety.
The European Commission has also restricted rue in food products. EFSA (European Food Safety Authority) assessments have noted concerns about the safety profile of rue-containing products, particularly regarding potential reproductive toxicity and the presence of potentially harmful plant constituents.
Regulatory Status
Rue oil is not approved by the FDA as a food additive and does not have GRAS status. This means it cannot be legally added to food products in the United States intended for general consumption. In the European Union, rue is not listed as an approved flavoring substance for food use. Some countries maintain historical or traditional use allowances, but these are generally subject to strict limitations and warnings.
The additive falls under the broader category of botanical extracts and essential oils that face increasing regulatory scrutiny due to safety concerns that cannot be adequately documented. Manufacturers seeking to use rue or rue-containing products must navigate complex regulatory frameworks that vary by jurisdiction.
Key Studies
Scientific research on rue has primarily focused on its phytochemical composition and potential toxicological effects rather than its safety as a food additive. Studies have identified the presence of furanocoumarins and other potentially hazardous compounds in rue plants and oils. Research has also documented traditional medicinal uses and associated warnings in historical medical literature regarding reproductive effects.
The lack of modern, comprehensive safety studies specifically evaluating rue oil as a food additive at typical food-use levels represents a gap in the regulatory approval process. Most regulatory decisions restricting rue have been based on known phytochemical composition and historical toxicological concerns rather than directed food safety research.