The Therapeutic Research Faculty (TRF) is based in Stockton, California and sets a high standard for its own ethics.
After subscribing to the Natural Medicines Comprehensive Database ConsumerVersion (NMCDCV), I found the following: “Bergamot oil is POSSIBLY UNSAFE in children when taken by mouth in large amounts. There have been serious side effects, including convulsion and death, in children who have taken large amounts of bergamot oil.” However, still no information source is given. This is frustrating, especially for a website that claims it is wholly evidence-based. The TRF website has this: “All data and recommendations by the Center and any of its publications are based on scientific data. Therapeutic Research Center supports the key elements of evidence-based medicine.” An outline of evidence-based medicine can be found here. If the NMCDCV or the TRF have any evidence for their assertions, they are certainly keeping it well hidden.
No cases of child poisoning from bergamot oil are evident on any publicly accessible database. All the available information indicates that bergamot oil is non-toxic, and to the best of my knowledge, there are no reports of poisoning, or convulsions, or death, in either children or adults. Bergamot oil has GRAS (generally recognized as safe) status. There are no safety cautions for either children or systemic toxicity in either the Merck Index, or in Martindale, The Extra Pharmacopoeia, and these are standard reference works for such reports.
The acute toxicity of bergamot oil in rats was found to be over 10 g/kg (Opdyke 1973). This means that at 10 g/kg there were no rat deaths, so the lethal dose was something greater than this, and 10 g/kg is equivalent to 700 g (24.7 oz) in a 70 kg (154 lb) human. This is an extremely non-toxic substance! I am not aware of any evidence that bergamot oil is convulsant, either in lab animals or humans. In fact its main constituent, limonene, is anticonvulsant (Carvalho-Freitas & Costa 2002, Sayyah et al 2004).
The caution in the NMCDCV is not backed up by any scientific evidence, and makes no sense in light of everything that is known about bergamot oil. The website does invite “comments or suggestions on something that should be reviewed or included” but clicking here brings up a box that says: “Use this form to e-mail technical questions to the web site designers. For medical questions or any other questions about the use of any of the products listed on this web site, please contact your health care provider.” (Bold type not mine).
So is bergamot oil safe to use on children? We know that the oil is not acutely toxic, and all of the major constituents (limonene, linalyl acetate, linalool) and most of the minor constituents of the oil are known to be safe in terms of systemic toxicity (Tisserand & Young 2013). So a truly massive amount would have to be used in order to produce serious toxicity. A 3 year-old child weighing 14 kg (31 lb) would have to drink 140 g (4.9 oz) to attain the 10 g/kg level that was not quite lethal in rats.
No cases of bergamot oil poisoning have been reported, perhaps because few consumers possess large enough bottles of bergamot oil, and even if they did, that’s a lot of essential oil to drink! Bergamot oil is photosensitizing (see Safety note below), and this is a very important issue in terms of skin safety, but otherwise there is no particular reason for caution in children. There are a few moderately toxic essential oils, but bergamot oil is not one of them, in fact it is one of the least toxic of all essential oils. In my opinion, the claim that bergamot oil can cause convulsions and death in children is baseless and irresponsible.
Bergamot oil is photosensitizing, meaning that if applied to the skin at certain concentrations, burning can occur if the skin is also exposed to ultraviolet light. To avoid this, bergamot should not be used at more that 0.4% dilution on the skin, or if it is, the person should not go outside during daylight for 12-18 hours (Tisserand & Young 2013). Alternatively, bergapten-free bergamot oil can be used, as this is not phototoxic. This warning applies to “leave-on” preparations such as oils, lotions and balms. There is no risk from “wash-off” products, such as soaps, shampoos and bubble baths.
Carvalho-Freitas, M.I., Costa, M., 2002. Anxiolytic and sedative effects of
extracts and essential oil from Citrus aurantium. Biological &
Pharmacological Bulletin 25, 1629–1633
Opdyke, D.L.J., 1973. Monographs on fragrance raw materials. Food &
Cosmetics Toxicology 11 (Suppl), p. 1035
Sayyah, M., Nadjafnia, L., Kamalinejad, M., 2004. Anticonvulsant activity
and chemical composition of Artemisia dracunculus L. essential oil. Journal of
Ethnopharmacology. 94, 283–287
Tisserand, R., Young, R., 2013. Essential Oil Safety, Churchill Livingstone, Edinburgh, p. 211