Re: you cant keep a good herb down
Not scientifically referenced but a basic introduction to Oregano Oil and why you have to be careful. Often it is not due to the idea of Oregano but the actual source; often it is not oregano oil at all.
http://health.enotes.com/alternative-medicine-encyclopedia/oregano-...
'Here's what the following authors say about Oregano and Thyme oils:
Sheppard-Hanger, Sylla
The Aromatherapy Practitioner Reference Manual, Vol. 1, Vol. 2.
Tampa: Atlantic Institute of Aromatherapy. 1997.
Oregano Essential Oil Origanum vulgare L.
No formal testing; avoid in pregnancy, on babies, children; likely irritant; avoid on sensitive skin; hepato-toxic in large doses.
(Note, I have found no scientific statements to confirm hepatotoxicity and point you to
http://home.caregroup.org/clinical/altmed/interactions/Herb_Groups/...
Thyme (Red Thymol) Essential Oil
Thymus vulgaris L.
Tested at low levels non-toxic (permitted food flavoring); highly irritant; non-sensitizing; not for use on damaged or sensitive skin; inhalations may be preferred over massage and bath; avoid with pregnancy, high blood pressure; hepato-toxic (?) in large amount and prolonged use.
Tisserand, Robert and Balacs, Tony
Essential Oil Safety.
Edinburgh: Churchill Livingstone. 1995.
Oregano Essential Oil Origanum vulgare L.
Hazards: moderate skin irritant, strong mucous membrane irritant. Cautions (dermal): Hypersensitive, diseased or damaged skin, children under 2 years of age. Cautions (inhalation, rectal, vaginal): Do not use at more than 1% concentration on mucous membrane. Toxicity data & recommendations: Undiluted oregano oil was severely irritating when applied to mouse skin and moderately irritating when applied to rabbit skin. Tested at 2% it produced no reaction after a patch test on human subjects. Comments: True oregano is Origanum vulgare, the herb used in the kitchen. However, the essential oil most commonly used in Europe is distilled from Thymus capitatus, and most safety data refer to this oil. Oils from many origins, as detailed above, may be offered as "oregano" or "origanum" oils.
Thyme (Red Thymol) Essential Oil Thymus vulgaris L.
Hazards: moderate? dermal irritant, strong mucous membrane irritant. Cautions (dermal): Hypersensitive, diseased or damaged skin, children under 2 years of age. Cautions (inhalation, rectal, vaginal): Do not use at more than 1% concentration on mucous membrane. Toxicity data & recommendations: Animal tests make thyme oil appear less toxic than would be expected from its content of thymol and carvacrol. Undiluted thyme oil was severely irritating to both mouse and rabbit skin; tested at 12% it produced no irritation on human subjects.
Schnaubelt, Kurt
Advanced Aromatherapy.
Rochester, Vermont: Healing Arts Press. 1998.
Oregano Essential Oil
Origanum vulgare L.
Contraindications: not to be used on the skin...because its phenols can cause varying degrees of skin irritation, it recommends itself for internal use. Ideally oregano oil is taken in a carrier oil, such as sunflower. The amount of oregano oil should be about 50 milligrams (equivalent to 1-2 drops) per application...In general, use of oregano oil should be limited to treating acute conditions. The French aromamedical literature advises that the long-term use of this oil, or generally oils with a high phenol content, can lead to undesirable changes in the liver metabolism.
Thyme (Red Thymol) Essential Oil
Thymus vulgaris L.
Contraindications: not to be used on the skin...Note: This oil should not be applied externally.
Watt, Martin
Plant Aromatics.
Tampa, Florida: The Atlantic Institute of Aromatherapy. 1995.
Oregano Essential Oil Origanum vulgare L.
A 2% solution of Origanum oil caused no irritation or sensitization on humans.
Thyme (Red Thymol) Essential Oil Thymus vulgaris L.
An 8% solution of Thyme oil (red unrectified) cased no irritation or sensitization on humans. Both Thyme oil and thymol have been recorded as being a cause of adverse dermal reactions including dermatitis, cheilitis and severe inflammation. Through personal experience and from unrecorded cases I have heard of, Thyme oil can be highly irritant on some people. In my opinion contact with the skin should be strictly limited to local treatments. The greatest care must be taken to avoid getting Thyme oil in the eyes and its use in baths should not be considered except for specific medical conditions under professional guidance. All chemotypes of thyme other than the thymol/carvacrol type should be treated as untested oils and appropriate precautions should be observed.
Neither one of these oils are considered sensitizers but I do think it is wise to seriously consider what these experts recommend for safe use. Just because something is safely used by one individual or by a company group surveyed, does not mean it will be safe for everyone in every situation. Companies promoting very bold use of essential oils contribute to members of the public assuming they can make up their own regimen of use and end up hurting themselves. I found an interesting but sad story in Salvatore Battaglia's The Complete Guide to Aromatherapy. Included in his precautions about Eucalyptus essential oil he wrote "There is a reported incident where, for about the past five years, a man had been in the habit of swallowing five to ten drops of eucalyptus oil to keep colds at bay and to 'make him feel good'. He began to feel discomfort and pain in the region of the liver. After entering hospital for a checkup, he was informed that he had been diagnosed with cirrhosis of the liver and that, unless he stopped drinking, his condition would further deteriorate. This man had never drunk alcohol. The apparent cause of his condition was the ingested eucalyptus which he had assumed would improve his health."'