Robert Tisserand interviewed on ingestion, dilution and other safety issues

In December 2014 I was interviewed by Labron Allen, a functional medicine nutritionist based in Texas, for his Health Alert radio show. This is a full transcript of the podcast, which you can find here or here. Many thanks to Anne Bankowski for the transcription.

Labron Allen

Labron Allen

I’m your host Labron Allen: This is Health Alert. Grab your cup of coffee, find your most comfortable chair and have a listen this Saturday morning.

If you remember last week I promised that I was going to have a special guest, and indeed I will deliver on that promise. This entire show will be about essential oils – there is so much popularity in the use of essential oils. Indeed I use them myself on a daily basis typically and they can be powerful tools. However because of so much popularity with their use and different companies coming into the picture, there has been a lot of marketing hype and there has been just general misinformation about the use of these essential oils and some people are experiencing rather adverse effects based upon what they’ve heard from others in how to use these different types of products, these different kinds of essential oils.

So this morning I have a real treat for you and our guest’s name is Robert Tisserand. Robert is an international speaker, he is an educator, and he is a consultant in the essential oil industry and profession. He’s been instrumental in bringing widespread professional and public recognition to aromatherapy itself. He started way back in the 1960s and now in the past few years he’s inspired live audiences on four different continents, including in Prague, Beijing, and San Paolo.

He keeps track of all published essential oil research, he collaborates with medical doctors, herbalists, pharmacologists and he integrates the scientific data with holistic principles. Robert has forty years of experience in aromatherapy product development, and has an expert knowledge of essential oil safety. His 1977 book The Art of Aromatherapy has been translated into eleven languages, and his book Essential Oil Safety, which I highly recommend that you get if you’re interested in the safe use of essential oils, is an excellent reference. It’s also regarded by aromatherapists as the industry standard for safety guidelines. So without further ado here is Robert Tisserand.

Robert, how are you doing today?

RT: I’m doing great, how are you?

Robert Tisserand in Brazil

Robert speaking in Brazil

Very well, thank you. I want to really tell the audience of how much I appreciate you coming on the show because you have so many years of experience behind you and you can really give our listeners a unique perspective about essential oils which are about just booming in popularity today. So with your unique perspective, you have over forty years of experience in essential oils, you’re able to actually give the history of how essential oils have become so popular today, so can you tell our listeners about your perspective on essential oils?

RT: I got involved in the late sixties – early seventies when I was living in London and I would say at that time that aromatherapy was very much seen as a beauty treatment. You went for a massage, you had a facial, you felt good, it was a beauty treatment and that was it. In 1967 I came across a French book by Dr. Jean Valnet about aromatherapy from a more clinical, medical perspective. And that really made me realize that this was more than a beauty treatment, it was something that really fascinated me and has ever since.

LA: That’s really fascinating, so you actually are quite familiar then with the French method of essential oil use?

RT: Well I don’t know if there is a French method. There are a very small number of doctors in France that use essential oils and herbs as well as conventional drugs in their treatments and sometimes they will use essential oils intensively, usually because they are treating people with cancer or chronic infections that patients have had for years, and ingested essential oils are a really a great choice for treating chronic infections if you’re a doctor.

LA: I see. So that actually helps quite a bit with some of the misconceptions that seems to be common, especially in the Unites States, that there are many individuals who suggest to just ingest dhese different essential oils seemingly indiscriminately.

RT: Yes, I think that it gets confusing because people often refer to GRAS status, so they will say that this essential oil has GRAS status which means that it is generally recognized as safe by the EPA and the FDA. But actually what that applies to is the use of essential oils in food flavorings; specifically this only applies to food flavorings and not to other uses such as medicines. So GRAS status doesn’t mean this essential oil is safe to ingest, it means this essential oil is safe to use in food flavors, which yes does result in ingestion but the word ingestion is where the confusion happens because it is not a way of saying that this is OK to use as a medicine.

LA: Have you seen any cases where there have been detrimental effects from the ingestion of essential oils?

RT: The most common adverse effect from ingestion is simply stomach irritation. If you put essential oils in water and drink the water then there are two reasons this is not a good idea. One is that essential oils don’t dissolve in water and so it actually makes it harder for your body to assimilate the essential oil into its system because it’s not evenly dispersed. It makes it much harder for the body but it also means that you have little droplets of essential oils floating around in your stomach and this can lead to irritation of the very sensitive mucus membranes of the stomach. As you know there was a recent statement by Gary Young of Young Living saying, don’t apply essential oils to mucus membranes, which basically means don’t put them in your mouth.

drop and bottleLA: That is a very good point, exactly right. Continuing on the line with Gary Young, one of the other issues that I’ve really witnessed with individuals using essential oils commonly is that they also advertise the use of neat application of the essential oils without any kind of carrier oil to the skin. And I have seen personally in my clinical practice really creating different kinds of skin reactions, skin rashes, sometimes quite severe. What can you say about that subject?

RT: Well this subject has been quite well studied by dermatologists and there are a number of different regulatory authorities that do issue guidelines for to what extent essential oils should be diluted for application to the skin. This particularly applies to product manufacturers, so for example if you’re using lemongrass oil in a product, the IFRA (International Fragrance Association) guideline for lemongrass oil is 0.7% to avoid allergic reactions. So that is a sensible guideline. I think those kinds of guidelines are mostly very sensible guidelines, they make sense and they are trying to say that we don’t want people to have adverse reactions, we don’t want people to have allergic reactions, so this is a safe amount to use.

If you were to use lemongrass undiluted on your skin what you do is you increase risk, you increase the risk of you having an allergic reaction. You may not have one, but the risk increases greatly of that happening.

LA: And would the risk increase the more often you use the application of lemongrass?

RT: Indeed yes. Frequency is another factor in allergic reactions. So let’s say for the sake of argument, that you were using a 10% dilution of lemongrass but if you used that three times a day for a year that would also be a very high-risk situation.

LA: There are those who have even written a book such as David Stewart, The Chemistry of Essential Oils Made Simple (here is a review I wrote some time ago) and he claims in that book that actually allergic reactions – skin reactions of essential oils is not possible. How did that get started? Where did that statement come from?

RT: Well, That’s a myth. It’s true that the immune system will only react to peptides and proteins, which are quite large molecules because very small molecules such are found in essential oils, the immune system can’t recognize them and can’t mount an allergic reaction to those small molecules. However what happens when you put for example, cinnamon bark oil on your skin? Cinnamon bark contains a potential allergen called cinnamaldehyde. The cinnamaldehyde combines with peptides in the skin, with proteins in the skin, to form a new molecule. It’s called a peptide-hapten complex and the immune system can recognize a peptide-hapten complex. And so the end result is yes you can have an allergic reaction to cinnamon bark oil and hundreds of people have had allergic reactions to cinnamon bark oil. It’s one of the most allergen-prevalent essential oils.


Image: Luc Viatour,

LA: Along with clove and different essential oils such as that?

RT: Yes, ylang-ylang, clove, lemongrass – there are a number that are more high risk and as I mentioned earlier, there are guideline for all of these; sensible guidelines where if you dilute it sufficiently that reduces the risk to a negligible risk. There is no such thing as zero risk in this world but we reduce the risk to absolute minimum.

LA: Yes, exactly. As soon as you get in a car, you run a risk.

RT: Exactly, yes.

LA: So one thing that I did notice is which is actually good, on the Young Living Essential Oils website, they have an essential oil safety Frequently Asked Questions (here) where it seems that they are suggesting the use of carrier oils when you apply the essential oils to the skin. But in those FAQs, they are still referring to a reaction that may occur as a detoxification effect. Is it possible to also have a detoxification effect or is it if a person has any type of reaction on the skin that it is an allergic reaction?

RT: You cannot have a detoxification effect from putting essential oils on your skin. If your body is detoxifying that’s probably because you are entering a quite intensive cleansing program of one kind or another. That’s what causes detoxification. Applying something to the body does not cause detoxification. No, you can’t, it’s not possible. If you apply essential oils to your skin and you get an inflammation from that, then that is an adverse reaction. Always.

LA: So you would recommend that a person discontinue the use of that essential oil immediately?

RT: Oh, absolutely. There are three types of adverse reactions on the skin. One is phototoxicity and this has always been widely recognized as a risk. No one has ever said that phototoxicity doesn’t happen and it would be very difficult to deny it, because the results are so dramatic and so severe. And phototoxicity only applies to a very small number of, mostly citrus fruit, oils and if they are applied to the skin in very high dilution and then you go out in the sun, you can have a very, very bad reaction.

The other two types of reaction are allergy and irritation. And allergy and irritation are not the same thing. They are different but they look similar. If you have an irritation reaction once you stop using the product and remove the oil from the skin, then the reaction dies down very quickly. With an allergic reaction it tends to remain inflamed for many hours, sometimes longer than that, and it will come back every time you use the same product in the same dilution. Basically if you have an allergic reaction then your immune system has created antibodies to something in the product or the blend that you have used, and you can assume that you will have that allergic reaction for life now. So you really want to avoid them.

LA: Wow that’s very good information! Moving back to when you first mentioned how you became more interested in the clinical aspects of essential oils with the French book. Another large amount of confusion that I see is with the idea that there are different schools of thought or methods or whatever terminology you would like to use as far as the use of essential oils. How did this get started in your opinion?

RT: I think it got started because in the UK, in the early seventies through the eighties and with the development of aromatherapy over there, people were writing books, starting schools, giving talks – and I certainly was a big part of that – none of us were really talking about giving oils internally because this was bordering on medical practice. We all felt that this was not something we do, we’re basically massage therapists. We don’t give medicines orally; we’re not into internal medicine, that’s not what we do.

LA: You’re not medical doctors.

RT: No, not medical doctors, and not even herbal practitioners, so then in 1990 another French book came out – by Franchomme and Pènoël – and they came over to the UK, and also I think to the US, and they were saying no, oral is good, internal is good, intensive is good you should do this, you can do this, it’s OK. I think the problem is yes it is OK, so long as you know what you’re doing and just as you don’t play with surgeon’s knives or pharmaceutical drugs, you don’t play with these things. You use them appropriately if you know what you’re doing and I think the same applies to essential oils that, yes, you use them appropriately if you know what you’re doing.

And by the way, I have never said you should not ingest essential oils. You may think you heard me say that today. I have not said people should not ingest essential oils; I don’t believe it’s an absolute no-no. What I do believe is that you need to know what you’re doing. You need to know why you’re doing it; what dose you are taking; how long you are going to be taking it for; what the reason is. I don’t think essential oils are substances that we should use just pro-actively, because if you do get a viral infection, if you do get a serious illness and then you want to use aromatherapy and you have been dosing yourself with large amounts of essential oils for years, well now what are you going to do? Because your body’s already now habituated to these oils you have been taking. If you’re talking about very small amounts as you would use in food flavors – if we’re talking about one or two drops a day – that’s fine, that is OK, but if you’re taking a therapeutic dose of essential oils, if you’re taking 10 drops, 20 drops a day just because somebody told you it was a good idea, it’s not a good idea.

LA: So your recommendation would be for individuals to treat an essential oil as far as ingestion more like a pharmaceutical, with the same respect as?

RT: Yes. The way I’m looking at is if you’re sick, you take medicine and then you get well. That is the scenario that I’m picturing, so if you’ve strained a muscle then you apply a liniment, you apply a salve to that muscle, to that skin over that muscle and they often contain menthol and camphor and other essential oil constituents that goes through the skin to the muscle and it does what it does, but once the muscle ache is gone you don’t need to keep applying it, and it’s similar to the way antibiotics are taken. You take antibiotics so long as you need to, you take the course of antibiotics and then you stop. I’m not suggesting that we should be taking antibiotics at all, but it’s the same situation with essential oils. If you have an infection, if you have a respiratory infection, then yes you can inhale essential oils, you can apply them to your chest, whatever, while you’re sick and then you stop. That’s the picture that I am trying to paint.

LA: Understood, so basically what you are trying to say is that the prophylactic use of let’s say oregano essential oil at 15 drops a day is not a good idea?

RT: Not long term, it’s not a good idea, no.

LA: Understood. The other issue that I have seen is the terminology used regarding essential oils. I don’t think that there would be any argument from anyone that if you’re using an essential oil – that you definitely want to find the best quality and unadulterated oil, but there is use of terminology such as therapeutic grade, I’ve even seen clinical grade coming out into the market. Do you have any comments on that?

RT: Yes and these same people will tell you don’t use perfumery grade oils; well there is no such thing as perfumery grade. There is no such thing as therapeutic grade, or clinical grade. These are not grades that are independently verified, they are words that are marketing terms created by the company selling those oils so they will tell you that they are the only people selling clinical grade oils. Well yes, because no one else is making that claim, you are the only people selling what you call clinical grade oils.

Helichrysum italicum, courtesy Júlio Reis

Helichrysum italicum, courtesy Júlio Reis

LA: And they may have even registered that term as well, copywritten it.

RT: Exactly, they may have done. But also I mean if you’re buying sandalwood, frankincense, copaiba or helichrysum oil, you can only get these from certain wholesalers in the world. If you’re selling blue tansy, helichrysum or frankincense oils you’ve bought them from, in the case of helichrysum, the Balkans, in the case of blue tansy, Morocco. That’s where they come from. Everybody gets them from the same place. So one blue tansy oil isn’t different from the next, one frankincense oil isn’t all that different from the next. They come from the same suppliers, the same origins. So your sandalwood oil isn’t different from the next person’s sandalwood. It may cost a lot more, but it basically is the same oil, unless it’s been adulterated. Sure, we don’t want adulterated oils.

LA: Exactly. The comment that you just made is very, very interesting. So you are saying – let me move back just one second. I have heard from different sources, mainly MLM [multi level marketing] companies that they have traveled the world and sourced certain farmlands such as, for frankincense let’s say. They make it sound as though it’s their own private source for that company. If I understand correctly, what you’re saying is, that no matter what frankincense oil you purchase from any company that basically it has come from the same source.

RT: Well in the case of frankincense there are different sources. They are all in the same region of the world. You can’t grow frankincense in Idaho.

LA: Understood.

RT: You can’t grow frankincense in France. It comes from one region of the world, where that plant grows, the same with myrrh, the same with black pepper, the same with most of these plants. If we are talking about herbs like lavender, sage, thyme, rosemary, yes these are easy to grow in many, many different regions. And sure you can buy land, grow lavender or mint and that can form part of your supply. A problem that we’re seeing now in the aromatherapy world is that the market has got so huge that in same cases there are not enough plants to supply the demand.

We are now in a situation, that perhaps could have been predicted twenty years ago, where the aromatherapy market has grown and grown and grown, and there isn’t enough oil to go around. So plants – oils like frankincense, helichrysum and blue tansy are in very, very, very short supply. So, yes if you are a very large corporation and you have the dollar power to go and buy land in another country or basically take over the supply from a farmer – that sometimes happens. That does sometimes happen. Then you may be virtually in a monopoly situation. I haven’t seen that with an essential oil, but it does happen sometimes with a fragrance companies or with other large corporations because they want continuity of supply.

LA: Of course. Essentially though, if a person has gotten frankincense from the same area, the indigenous in which that plant grows, then for all intents and purposes the essential oil is of the same quality if it is not adulterated. Is that correct?

RT: Yes, it is, absolutely.

LA: That’s very interesting. So what do you see for the essential oil profession and industry? What would you like to see happen over the next twenty year period, as far as standards, as far as use of the essential oils? What would you like to see?

RT: One thing that I would like to see is the separation of sales and education. I made this comment on Facebook earlier this year and it didn’t go down very well because what I’m saying is if you sell essential oils then you shouldn’t be making medical claims, you shouldn’t be making any claims for your oils, you’re just selling oils and the education part should be done by somebody different, somebody wearing a different hat. People were saying well how will I know what my oils are good for? Well the fact is that the situation in the US is almost unique. In the rest of the world there is a separation of sales and education. Especially in Europe, you can’t sell a product and make a medical claim on the label, on the Internet, on a flyer, or anywhere. You can’t and people don’t. Unlike with the FDA the equivalent authorities in Europe actually do carry out what they say they will do. They enforce their rules, where as the FDA tends not to. It tends to say something and then do nothing about it.

LA: Right. So in Europe they will shut it down?

RT: Yes, absolutely. So the essential oil businesses in Europe, if you look at the websites, you won’t see any medical claim. Now when I say medical claim I mean no disease condition is mentioned. You can’t use words like pain, arthritis, or insomnia. You just can’t use those words at all. There is just no work-around. You can’t say “Has been known to help.” or anything like that. You just can’t use those words. If people are making claims they are using words such as warming, soothing, and calming. Innocuous words like that.

LA: No direct medical claims obviously.

RT: I don’t know if it will happen, but think it would be nice if there was a separation of sales and education because then in a way you get away from this situation where you have one company that’s telling you what their product does, what their essential oil does and trying to make a greater claim than the next company.

LA: Exactly. That happens all the time here in the United States for sure. The other things that I have seen going along with claims made is, I don’t know your opinion about it, but it seems to me that many times claims that are being made as far as the “medical uses” of the essential oils are actually of what the herb would be able to accomplish and not necessarily the essential oil. How do you feel about that?

RT: When I got involved in aromatherapy in the early 70s there was very little information about essential oils so it was tempting, I think for all of us at that time, to look at herbal texts and assume that, well, maybe the same things happen with the oil. I don’t think we need to do that now because one difference between now and then is that now we have a tremendous amount of research material; that scientific research has been happening in a big way for essential oils, for essential oil constituents, and there’s a great deal that we do know as well as from aromatherapy and from clinical practice. There is a great body of evidence there too. So we don’t need to borrow information from herbal medicine and if people are doing that then it can be misleading. Obviously some herb and herb extracts contain active constituents that are not found in the essential oil and so the effects are often different.

LA: Exactly, very good. What would your recommendations be for individuals who would like to learn good, solid information about essential oil safety and perhaps even some uses of essential oils? Where would you recommend that they go to do that?

RT: There’s online training, there are books, there’s a lot of free information on social media. Obviously I’ve written a book called Essential Oil Safety and I think it’s a good book.

EOS.Final copyLA: I think it’s pretty good too! I would highly recommend that anyone who is interested, get your book immediately. It is extremely well written and documented.

RT: There is one thing that I would like to say which is that, if we could put Gary Young, Young Living and David Stewart in one box, then what I used to hear coming from that direction was that essential oils, if they’re natural are totally safe apart from phototoxicity; apart from phototoxicity really there is nothing that can go wrong so as long as you are using the right brand of essential oil. And then I think two, three years ago I started to hear more cautionary messages. I started to hear that well yes, there are things that we are calling hot oils and if you get redness on your skin then you need to apply a vegetable oil. So there was an acknowledgment that skin reactions other than phototoxicity could happen. I think what we’re seeing now is quite a big change because as well as acknowledging adverse skin reactions, now there is talk about the possibility of interactions with medications… not using undiluted oils on the skin…the possibility of risks during pregnancy…and so I think the cautionary messages that we’re hearing now – and this is a good thing – I think there is a greater and wider recognition now that a number of different adverse reactions are possible. They are rare; they don’t happen very much but they are possible.

LA: Exactly right. Even in the FAQ document itself on line six, the last sentence in that line is that an excessive use of essential oils may increase the risk for adverse reactions which if it’s only a detoxification effect what could possibly be an adverse reaction than other than allergic reaction?

RT: Yes, I had the same thought.

LA: The other thing that I see going along with this is David Stewart’s book, basically this FAQ on the Young Living Essential Oils website is 180 degrees from what is being stated in the current edition of his book.

RT: Yes. I don’t know what people on the Young Living social media groups are saying to each other. That might be interesting to know. They might be feeling a little confused at this point.

LA: Alright. Well again, thank you very much Robert. I appreciate it.

RT: Fantastic. Good to talk to you.

LA: Good to talk to you as well. You have a good morning.

RT: You too. Bye.

LA: Bye.

LA: There you go folks. I hope that you have found this information very useful, especially if you have heard about essential oils, you’re thinking about getting into the use of essential oils or you are currently using essential oils I hope that you find this information very helpful to you.

Again, I mentioned at the beginning of the program that Robert has written several different books. I do recommend that you get his Essential Oil Safety textbook. It will prove to be extremely helpful to you if you do so.

Frankincense essential oil and cancer:
Why EOs and chemotherapy don’t always mix

My friend just started taking chemo for colon liver cancer and she was taking therapeutic Sacra Frankincense from Young Living before she started. I read somewhere that you should not take the essential oil with 5FU if you are taking it for skin cancer because it will drive it in the skin deeper and make the chemo 10 times greater. That sounded good to me, but for some reason they say not to use Frankincense with 5FU. Since she has colon liver cancer, and not skin cancer, should she just rub it on her feet and side, stop taking it, or take it internal, or not at all. I am not sure how to direct her at this time, but she has heard so much good about the Sacra Frankincense killing the cancer cells. Any help or suggestions would be welcomed and appreciated. Also, have you heard anything about stopping essential oils when you are on chemo. Someone also said, stop 2 days before your treatment and then start back 9 days later. My friend takes chemo for three days in a row using a pump and then 14 days later she starts again, so it gives her no time to use her oils.

My thanks,
Patti F.

Hi Patti,

Many essential oils have protective & antioxidant effects on our cells, and there is a reasonable chance that they will do the same for cancer cells – protect them from the chemotherapy – which of course would not be a good thing. This opinion is shared by many. It probably sounds odd – you’re thinking that frankincense oil should kill cancer cells and not protect them – but the only evidence for killing cancer cells (apart from one skin cancer report) comes from a few lab tests when high concentrations were used.

Moderate amounts of EO will not kill cancer cells, but could protect them. And taking large amounts of essential oil could very well interfere with the chemotherapy itself, by increasing or decreasing the concentration of drug-metabolizing enzymes in the liver. By causing a chemo drug to be metabolized more quickly, you reduce the duration of its effect. On the other hand if you inhibit its metabolism you reduce the efficacy of the drug. Neither of these is desirable, and chemo drugs are very carefully dosed for each patient.

For all these reasons, I suggest avoiding essential oils for one week before until one month after chemotherapy. After that time, frankincense oil may help with recovery of white blood cells, as also spearmint, dill and other essential oils.

Incidentally, almost all of the research on frankincense and cancer is on the extract, which contains boswellic acid, and not the essential oil, which does not. Frankincense extracts contain around 50% boswellic acid, which is a widely-studied antitumoral agent. However, getting such remedies to the target site in sufficient concentration to be effective is a challenge.


Thank you so much for the info and for taking the time to help in this matter. I will let her know to immediately stop the Frankincense until she is finished with the chemo.

Lavender mascara?

Adding lavender oil to your mascara has become a thing, on the basis that it will make your eyelashes longer and thicker, and also that it will deter eyelash mites. About half of us have tiny eyelash mites, but they don’t affect at least 95% of those who have them. They do not make your eyelashes thinner or shorter, though an infestation can make eyelashes fall out. Some argue that eyelash mites perform a useful function, by eating dead cells and debris. If the mites do indeed proliferate, the condition is known as demodicosis. This can happen in people with a severely deficient immune system, and there are significant associations between demodicosis and certain inflammatory skin conditions, especially some types of rosacea.

Demodicosis is treatable with tea tree products (ointment, shampoo, washes), in fact this is one of the most effective treatments known. For daily use, there is a product based on terpinen-4-ol, the major constituent of tea tree oil. This used to be only available to dermatologists. By all means use this or tea tree products for daily hygiene, but unless you have demodicosis, trying to totally eliminate eyelash mites that you can’t see may be pointless.

Woman applying mascara on eyelashesAs for lavender mascara, there’s no evidence that lavender oil has any effect on eyelash mites, eyelash length, or eyelash thickness. Adding lavender oil to your mascara is not necessarily dangerous, but it could be if it’s not evenly distributed. How do you mix the lavender oil in the mascara? The packaging and consistency of the product make even distribution of an essential oil challenging. And why are you doing it? Even if you add tea tree oil instead of lavender to your mascara, it’s not likely to have much effect on eyelash mites (which you might not have anyway). Maybe it will keep them off your lashes, but it won’t get to them where they spend most of their time – inside your hair follicles. So my advice is, don’t mess with your mascara, but maybe look out for tea tree face washes.

A word of warning – do not apply undiluted tea tree oil, or any other essential oil, to your eyes – very bad things can happen! (In one of the above links you will see “apply a couple of drops of tea tree oil to the lashes”. Don’t!)

Bergamot Oil – Toxic To Children?

I was recently contacted by an essential oil business (Plant Therapy) which had several customers ask about the safety of bergamot oil, as they had heard it could be lethal and cause convulsions in children. The sources of this warning appear to be and, as both websites have profiles on bergamot oil that include this:

“Do not use bergamot oil in children. There have been serious side effects, including convulsion and death, in children who have taken large amounts of bergamot oil.” These are no doubt widely-read websites. The WebMD information is quoted by Wikipedia. Both websites give the following source for all their information:

This copyrighted material is provided by Natural Medicines Comprehensive Database ConsumerVersion. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version. © Therapeutic Research Faculty 2009.

Citrus bergamia

Citrus bergamia

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).

sloppy science

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.

Safety note
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

China Report 2014

On Thursday July 24th, I left home for my second visit to the People’s Republic of China! (see report and video of my first visit here, and pics here) This time I was invited by a Beijing-based aromatherapy school, Floralwish. The most obvious difference from my 2011 trip was the weather – instead of November’s freeze, I encountered a very warm and humid August, with average temps of around 90F. And this time, after my weekend seminar in Beijing, I was going to repeat it a week later in Shanghai, providing time for some sightseeing in between.

After my 13 hour Air China flight I arrived in Beijing at 5.40 am. Ellen, the Floralwish owner, and Orange and Joanna, my guides for most of my stay, took great care of me, and welcomed me with an immaculate placard! After a 90-minute drive across the city we arrived at the Lakeview Hotel, which would be my home for the next few days as well as the venue for the first seminar. The hotel is a part of Beijing University Campus and is busy with guests and conferences. It has an amazing courtyard garden with waterfalls, duck ponds, lotuses in flower, and tress that included apricot, weeping willow and gingko biloba.

Lakeview hotel gardens

In the afternoon I met with Liza, who would be my translator for both the events. (People in China often try to make it easier for us to remember their names by choosing a westernized one.) Liza has a degree in TCM and specializes in cancer treatment. When we met she had already taken extensive notes, especially for the names of constituents. We were able to run through the presentation quite quickly to make sure everything was clear.

RT in ChinaFriday was a day of rest and final preparation for the event, and on Saturday morning I made my way to the seminar room. The 65 attendees arrived at 10.00 am, keen to acquire new information about how to use essential oils with minimal risk. On the first day I covered general topics such as the difference between hazard and risk. I used an analogy about crossing streets in Beijing – there is hazard, but various factors increase or decrease actual risk (such as speed of traffic, amount of traffic, and how good your vision is).

I also talked about different types of evidence (in vitro, in vivo, clinical etc), and the different methods of administration and their specific constraints. There was a lively discussion about long-term inhalation. I recommend that a 30-60 minute period of inhalation should be followed by inhalation of “clean air” for the same amount of time to avoid adverse effects. I call this intermittent inhalation, or diffusion. For very low levels of fragrance, barely perceptible, it’s not important.

We also discussed the pros and cons of patch testing in some detail. In general, I don’t feel it is necessary unless there is a known problem. At the end of the day there was a group discussion and revision of all that had been covered.

On Saturday night there was a special gastronomical treat. The organization team and translator, four amazing women, took me to a popular “hot pot” restaurant. Set into the middle of the table were two rectangular containers filled with seasoned water, one spicy and one not, placed over gas burners. As the evening progressed, various foods were dropped into the boiling water – from chicken, lamb and beef, through tofu of all kinds and forms to duck tongue and a cuttlefish meatball, which was quite delicious. We were also treated to what might be described as a “noodle dance”, similar to the tossing of pizza dough. One of the staff appeared by our table and proceeded to stretch out flat noodles made of tofu till they were perhaps 6 feet long, at the same time dancing them through the air in fast-moving ribbons. He then deftly shortened them with his (gloved) fingers, and tossed into the boiling pot. I was impressed, and the noodles were very tasty.

Dinner in China

Back at the seminar on Sunday, we successfully negotiated the safety aspects of some weight subjects including cancer, pregnancy, drug interactions and phototoxicity. We paused occasionally to make sure that plant names were being correctly translated (botanical names are not much used in China), and there were questions about the use of wintergreen oil together with blood-thinning drugs. The issue of whether and which essential oils can be used to help treat cancer was raised. In response to this I talked about research on perillyl alcohol (mainly for brain cancer) and Zedoary (Curcuma zedoaria) essential oil (liver cancer). Perillyl alcohol is a constituent of Perilla frutescens oil, which is produced in both China and Japan, but is not well known outside Asia. See more on this emerging research. As always in Asia, there was an extensive photo session after the event.

There was a pre-arranged magazine interview on Monday afternoon with Modern Brides. The editor wanted to know the various ways that essential oils could be used to help married couples. She asked many questions in the area of relaxation, mood changers, aphrodisiacs, and which oils would revive a “tired” relationship. At one point I talked about creating an “anchoring” blend by using it during a vacation to build an association with feeling good, and then afterwards bringing out the blend only when really needed. I also suggested that a blend of bergamot, sandalwood, frankincense and jasmine would be useful for “feelgood” and sensuality. After the interview we drove into the center of Beijing for lunch, and to visit the Floralwish premises, which are located in a Hutong area.

On Tuesday, Orange and Joanna took me to the Great Wall, specifically to a part called Badaling. As we approached the area, hills seemed to suddenly spring up, and then we could see the wall hugging both peaks and valleys. It is of course a stunning feat of engineering, with millions of heavy stones perfectly laid across hilly terrain. This section was built in 1504, and is maybe a mile in length. Very few sections are flat, and some are very steep, and stepped. After a couple of hours of wall-walking (to the end of this part and back again) we had a much-needed lunch, and then drove back into Beijing.

On Wednesday I visited Darren Moore and his family. Darren had been my host in 2011 and it was great to see him again. He is Canadian, and settled in Beijing when he fell in love with a local girl. As well as making natural soaps and cosmetics (he does not even like to use emulsifiying agents for lotions) his mission is to inspire others to return to a more local, organic and small-scale style of living. New to me was a walled vegetable garden, where he has green beans, fruit trees and a lot of sweet corn. We visited a local park where we saw hundreds of coi carp in a pond being fed. For dinner we drove to an artists district where we ate lamb skewers and some delicious thin, black noodles made from fern. Thursday was another rest day, and Friday was a travel day.

Due to some political issues, many domestic flights in China were delayed or cancelled so it was decided that we would take the train to Shanghai instead of flying, as had been planned. At Beijing train station I said goodbye to Ellen, who would not be coming to Shanghai. The journey was fast and smooth: traveling at 200 mph, it took only 5 hours to travel almost 1,000 miles and we crossed the two longest bridges in the world, the Danyan-Kushan Grand Bridge and the Tianjin Grand Bridge. As we traveled through the city of Nanjing I discovered that the name means “capital of the south”, while Beijing means “capital of the north”. After a long drive from the train station we arrived at the hotel, which again was also the venue for the seminar. My room at the Wyndham Bund East Shanghai hotel had stunning views of the Huangpu river and the Yangpu bridge that crosses it.

Shanghai is different to Beijing in many respects. The architecture is more European, the air is less polluted, and the food is sweeter and less spicy than in Beijing. Unfortunately, I found the espresso coffee in the hotel undrinkable, but the choice of rice, tofu, veggies etc at breakfast was very welcome, as it had been in Beijing.

There were 30 attendees at the Shanghai seminar, including, unusually, 5 guys. A few participants spoke excellent English and one lady had travelled from the Philippines for the event. Liza was already familiar with my material of course. Among the questions asked was the issue of fennel oil and its probable estrogenic action. We know that fennel tea, apart from relieving colic, promotes production of breast milk, and I have recommended that the oil should not be used in either pregnancy or breastfeeding. I am now wondering if I should reconsider my breastfeeding ban for fennel oil.

Shanghai group photo

Sunday was my last evening in China and I was given a spectacular send-off. Dinner was in a Thai restaurant in the exciting Bund area of Shanghai, which at night is spectacularly lit. The restaurant was on the riverbank with magnificent views of the brightly lit skyline of Shanghai, and the food was amazing. But it seemed as if China wanted to make my trip especially memorable, and just as we finished our meal, a major firework display began on the other side of the river. We walked out to the riverside to watch it. Even the restaurant staff seemed surprised. On Monday, after packing, signing attendance certificates for both events, and having a quick lunch in the hotel, I left China and flew back to Los Angeles. It was an inspiring and memorable trip.

Essential oils and gut flora

In a blog post dated July 13th 2014, Madhupa Maypop quoted Paul Bergner, saying: “The scent of an essential oil can kill gut flora just like antibiotics do, according to Paul Bergner, director of the clinical studies program at the Rocky Mountain Center for Botanical Studies. He told me that breathing the oils puts them into the blood stream very quickly and can be a major disturber of intestinal health and contributor to poor immune functioning.” However this quote has now been removed from the post, since Paul Bergner has denied that he ever said this. Paul contacted me directly on July 15th, saying: “I have never said, or even thought, that inhaled essential oils could have any effect on the gut flora. There may be a theoretical concern about taking undiluted oils internally, but this has never been demonstrated.” The original Paul Bergner quote in fact comes from Susun Weed’s website. Paul has asked Susun to remove the misquote from her site.

It is true that inhalation of essential oils results in most constituents getting into the bloodstream (it’s not correct to speak of “essential oils” in the blood, since individual constituents are not equally absorbed). The same is true of any mode of application, though generally the amounts in the blood are in the range of 1-100 nanograms per mL of blood – quite low concentrations. Whether these constituents might then negatively affect the bowel flora is pure speculation.

Fit and slim female model exposing her belly and waist

We do know that enterically-coated capsules of peppermint oil are beneficial in cases of irritable bowel disease and that these capsules result in a (substantial) peak serum concentration of 1,492 ng/mL for menthol. We also know from this report that peppermint essential oil had a beneficial effect on the balance of gut bacteria in a case of SIBO (small intestine bacterial overgrowth).

It would be useful to know more about particular oils, doses, routes of administration and their effect on the body’s microbiome. But in the meantime, it is rash to assume that essential oils negatively affect the balance of bowel flora, because there is no clinical evidence that this happens. On the other hand, decades of clinical experience by doctors in France suggests that essential oils frequently heal both acute and chronic infections without the damaging, and often long-lasting effect on bowel flora that comes from the use of antibiotics.


EO Inhalation and Seizures?

Hi, I have a question regarding a possible adverse reaction to Young Living eucalyptus oil. A friend of mine was mopping her floor with some eucalyptus oil diluted in her mop water. The same day, her three year old had a seizure. He had never been diagnosed with a seizure disorder of any kind. He was taken to the ER and received several tests with inconclusive results. My friend did not make any connection between the oil and his seizure. About a week later, exactly the same series of events occurred. The second seizure lasted 24 minutes. She discarded the oil. Her son is still having seizures and was diagnosed with status epilepticus. He did not ingest the oil. The only routes of administration would have been diluted on bare feet or inhalation. Pure coincidence or a reaction with neurological damage?


Hi Amber,

Seizures are possible from essential oil inhalation, though rare. Seizures from eucalyptus oil are also very rare but do happen, and the younger the child the more susceptible they are to seizures. One case was reported in 2011 from a girl who used a head lice repellent lotion containing 11% eucalyptus oil. The same sequence of events happening does suggest a causal connection.

Best wishes,

Why Is Essential Oil Dilution Important?

dilutionHi Robert,
I’m having some trouble understanding my essential oil dilution research and was hoping you could clarify for me.

1.) Why is dilution so important if 95% of the oil evaporates when applying topically?

2.) Is dilution recommended due to sensitivities that could occur? I have used oils neat before and never had an issue.

Thank you for your time,

Hi Danielle,

It partly depends on why you are applying essential oils, and why to the skin. Much of my teaching is about cosmeceutical effects and products for skin care. Dilutions of essential oils are generally more effective in this area, because the skin does not respond well to concentrated EOs. They are drying, the risk of adverse reactions is increased significantly, and for skin care/personal care you simply do not need more than 1-5% essential oil.

About 5% of applied EO is absorbed into the body through the skin, but more if undiluted oils are used. When you first apply an EO to the skin, 100% of it is there for a while. This is when any adverse skin reaction will occur, so while it is true that most of it evaporates with time, this is not as relevant as the initial dilution.

Essential oil dilution is important for two safety reasons. One, to avoid skin reactions: irritation, sensitization and phototoxicity. Two, to avoid systemic toxicity, such as fetotoxicity, hepatotoxicity, carcinogenicity and neurotoxicity. Adverse skin reactions are obvious when they happen, but systemic toxicities may not be. Skin reactions are totally dilution-dependent, and safety guidelines exist to minimize risk. This does not mean of course that every time a person uses an undiluted oil there will be an adverse reaction. Many times there won’t. But more is not always better, and minimizing risk is generally a good idea. A phototoxic reaction for example, can be very, very nasty.

If you want to know more about what can go wrong and why, I would recommend my book Essential Oil Safety 2e.


Prague Report

RT in PragueIn 2013 I was invited to give a weekend presentation to the Czech Aromatherapy Association, and we set the dates for April 26/27 2014. On Thursday, April 24th I arrived at the airport in Prague, and was met by Jaromir and Blanka, who then took me on a one-hour drive around their beautiful city en route to the Hotel Step. Many of the existing structures date from the 14th century.

Friday was just for sightseeing on foot, and I was accompanied by Katerina Hroudova, Marie Noe and Hana Belikova. Hana would be my translator for the event. We saw some beautiful gardens with blooming lilacs, fragrant peonies and a Cedrus atlantica tree, and many statues, frescos and ancient walls, ending with perhaps the main tourist spot – the Charles Bridge. The coffee in Prague is excellent by the way.

How it turned out
Everything was set up perfectly on Saturday morning, and after some introductions I got started with my presentation, which was all about safety. This is a necessarily technical subject, and has the potential to be terminally boring, especially with translation slowing things down to half speed. But, there were three factors that made the weekend work.

One, I included some positive information about aromatherapy, all of which was relevant to the subject matter. When I talked about some in vitro testing that shows lavender oil to be cytotoxic to skin cells, I also showed evidence to the contrary, and illustrated the skin healing effects of lavender oil. This was part of a discussion on the relevance of in vitro testing. Two, the translation was excellent. At one point I said to Hana “you’re doing a great job” and she retorted “how do you know?” OK, I don’t understand any Czech, but when the translation is immediate, speedy and confident, it’s a very good sign. And, Hana is a professional translator, as well as being an aromatherapy enthusiast.

Three, the audience understood what I was saying! You can tell by facial expressions and body language, and also by the questions asked. I don’t just mean that the translation was effective, but that they understood the technical content and could see the connections I was making between constituents, oils, properties, hazard and risk. This suggests a thorough aromatherapy knowledge and training.

Seminar content
Clinical Safety, Prague Cz, Apr 2014The Saturday presentation included several slides showing different types of adverse reaction, the difference between hazard and risk, types of evidence, weight of evidence, inhalation, ingestion, transdermal absorption, and metabolism. Michal Babka, asked a question about dosage for animals, and I answered that this would be, as with humans, related to body weight. He mentioned that he had used essential oils to help a giraffe in the Berlin zoo.

On Sunday we talked about risks involving cancer, pregnancy, drug interactions and skin allergies. These subjects were not covered in their entirety, but examples were given illustrating key points. I also covered phototoxicity. This was not originally planned, but I realized early on that I needed a little extra material to fill the day. Following a question, there was a discussion about whether any fatty oils had any scientifically established SPFs. The outcome – probably not, because the existing research evidence does not meet regulatory standards.

When we got onto drug interactions, a pharmacist asked about whether grapefruit oil would interact with statins, cholesterol-lowering drugs, as grapefruit juice does. My answer was no, since the main compound in grapefruit juice responsible for drug interactions is not found in the essential oil.

Most of the audience was Czech of course, but there were also a few who had traveled just for the event, including Eva from Spain (who understood my English, but not the translation) a lady from Russia (who understood some English and some Czech) and a Greek lady who lives in Canada. I signed many books, including two of my older books written in Czech, and copies of the new Essential Oil Safety, which Marie, a publisher, was selling.

I was disappointed that Katerina Svoboda was not able to be there, but I was given a written note from her, which was a pleasant surprise. Katja has spent most of her career in essential oil research, and co-authored a book showcasing the kind of pictures of essential oil glands that illustrate the new Essential Oil Safety cover. We have known each other for many years.

On Monday April 28th, I made my way back to Ojai California with many new friends and pleasant memories.

Click here for the Czech language version of this content.
Klikněte zde pro české jazykové verze tohoto obsahu.

Australian Tea Tree Industry Insights

I spoke with Tony Larkman, CEO of the Australian Tea Tree Industry Association, about the nonprofit he heads, his own introduction to essential oils, and issues facing the essential oils industry and tea tree oil in particular.

Tony Larkman, ATTIA CEO

Tony Larkman, ATTIA CEO

Tony Larkman was born and raised in Kenya. After travelling extensively through Africa, Europe and the Middle East he returned to East Africa in 1986 to work first as a purchasing officer and then as a pig farmer before moving to Australia in 1992. Over the next 17 years Tony turned his hand to feed milling and grain trading before becoming an IT Manager and then a Purchasing Manager. In 2009 he started working for ATTIA Ltd where he realized that he had finally stumbled on the answer to a question that had plagued him since he was child: “What do you want to be when you grow up?” Tony is now the CEO of ATTIA Ltd which is probably the most organized and active industry body for any single essential oil.

RT: Your introduction to tea tree oil was as a pig farmer?
TL: It was the mid-1980s, and a spray bottle of ‘healing oil’ with tea tree oil as the active ingredient was hung near the door of every building on the piggery. We used it everywhere and for everything, for both workers and animals – from minor cuts and scratches through to cleaning and preparing wounds for stitching after fights between boars – some of which were horrendous and likely to have been fatal without the magic of the healing oil. It also helped mask some of the smell of a piggery, which was a bonus.

What is ATTIA, and what services does it provide?
The Australian Tea Tree Industry Association (ATTIA Ltd) is an Australian based not-for-profit organization formed in 1986 as the peak body to promote and represent the interests of the Australian tea tree industry. From the grower/producer to the manufacturer of off-the-shelf products for public use, ATTIA supports and promotes the responsible use of pure Australian tea tree oil (TTO). ATTIA’s aim is to develop a stable, cohesive, environmentally friendly, and internationally competitive TTO industry producing quality assured TTO that meets or exceeds international standards. ATTIA promotes the safe effective use of TTO for a wide range of applications. More information about ATTIA here.

Full membership of ATTIA is open to all Australian tea tree industry participants while associate membership is open to international participants in the supply chain. Our services include:

  • Support and advocacy in dealing with government and regulatory agencies, research and development groups and the media.
  • Leadership and representation in the formulation of overall industry strategy.
  • Generic industry promotion at national and international levels.
  • The collection and compilation of market data to inform all links in the supply chain of factors influencing supply and demand for pure Australian TTO.

Australian Tea Tree Industry Association

Is the ATTIA website useful for consumers, enthusiasts or practitioners?
ATTIA’s website was created to cater to all levels of interest from school children preparing a project through casual consumers and passionate enthusiasts to professionals. The most commonly accessed pages which are easily navigated to by using the drop-down boxes in the navigation pane at the top of every page are:

Home Page A summary of who ATTIA is and where pure Australian tea tree oil comes from.
About Tea Tree A more in-depth look at production, uses, safety and efficacy.
FAQ Answers 20 of the most commonly asked questions on tea tree oil.

For professionals and researchers there is also a regularly updated, searchable Literature Database where detail on more than 1,200 papers can be accessed. These include most articles published on the safety, efficacy and uses of pure tea tree oil since 1904 when the species from which pure tea tree oil is distilled (Melaleuca alternifolia) was first described by Maiden & Betche.

Australian Tea Tree harvest

Harvesting tea tree. Picture courtesy of Mark Webb

How much tea tree oil is produced annually in Australia and around the world and to where is it distributed?
We know that between 400 and 500 metric tons of pure Australian TTO is produced annually; this is dependent on the weather and growing conditions from year to year. 80% of this is exported, most to North America. In 2012 a total of 409 metric tons of Australian TTO was exported to the following destinations:

  • 50.27% North America (USA, Canada, Mexico)
  • 25.66% Europe (Continental Europe, UK, Russia)
  • 22.76% Asia (India, Middle East, South East Asia, China, Japan)
  • 0.98% Africa (South Africa, Egypt)
  • 0.33% South America (Brazil, Chile, Colombia)

Tea tree oil is also produced in several other countries including China, South Africa, Kenya, Indonesia and Thailand. All of this TTO is produced from Melaleuca alternifolia, an Australian native tree that originated in the coastal regions of Southern Queensland and Northern NSW. No one can accurately state how much TTO is produced in these other countries.

Are there different qualities of tea tree oil?
Let me clarify first that there is no ‘pharmaceutical grade’ of TTO, nor is there a ‘therapeutic grade’. These are purely marketing inventions intended to convince a buyer that a particular brand is in some way superior to that of competitors. The main ingredient and most active bacteriostat in TTO is terpinen-4-ol which, according to the current standard, must be between 30% and 48% in TTO. Almost all pure Australian TTO is traded today with 40%+ terpinen-4-ol. The only way to make sure you are getting the best available TTO is to ask the retailer or manufacturer if they are using pure Australian TTO and how they verify this. If they can’t (or won’t) answer then either they are cheating or they genuinely don’t know. If the latter is true please refer them to the ATTIA website or Facebook page.

The second great marketing myth that has been roundly debunked in scientific literature is the belief that the level of another compound invariably found in pure Australian TTO: 1,8-cineole, needs to be as low as possible to prevent irritation. Today’s standard allows up to 15% of 1,8-cineole (which is actually the main constituent of another Australian native essential oil – eucalyptus oil – which contains around 80% of 1,8-cineole, or eucalyptol as it is also known) and there is clear evidence  that it makes no difference in TTO at levels of up to 8%.

Pure Australian Tea Tree Oil

The ATTIA Code of Practice seal

Tea tree oil is steam distilled from the leaves and terminal branches of the Australian native tree Melaleuca alternifolia. When correctly distilled, stored and shipped any oil extracted from M. alternifolia is just as safe and efficacious whether it is produced in Australia or anywhere else in the world. In Australia all production, distillation, storage and shipment processes are stringently controlled through the ATTIA Code of Practice (COP) quality assurance program to guarantee that only pure, natural TTO derived from M. alternifolia is supplied in perfect condition to discerning manufacturers both locally and around the world. In other countries issues related to pesticide use, identification of source plants, poor distillation, as well as poor handling and storage practices can contaminate or degrade the oil to the point where it is no longer safe to use and cannot even be described as tea tree oil.

                                “TTO has an enviable reputation for its

                                antibacterial, antifungal, anti-inflammatory,

                                anticancer and antiviral properties”

In addition to these quality assurance issues, as TTO passes up the supply chain, some unscrupulous suppliers and traders deliberately contaminate it with byproducts that are derived either from other essential oils such as pine oil or from synthetic production processes. This adulteration can significantly compromise the safety and efficacy of the product when used as a replacement for pure TTO. In some instances I believe this practice has led to TTO being abandoned as a traditional herbal product because either ‘it doesn’t work’ or ‘it causes irritation’. The most frustrating part of this for ATTIA is that the claims made by those who sell the adulterated material are based in the main on ATTIA sponsored science into the safety, efficacy and uses of pure Australian TTO. More information on adulteration is available from a Facebook site, which was created specifically to raise awareness of adulteration in TTO.

These days pure Australian TTO is traded in commercial quantities using the International Standards Organization’s standard ISO 4730:2004 but the oil typically has 40% or more terpinen-4-ol, and a maximum of 3-4% 1,8-cineole, depending on the buyer. Occasionally you can still see “T39-C2”,”T39-C4” or “T40-C4” on some bottles; all they are doing is trying to differentiate their product from that of their competitors. The fact remains that there is clear scientific evidence that pure TTO is just as safe and effective regardless of the levels of terpinen-4-ol or 1,8-cineole as long as it conforms to ISO 4730:2004 standards. More information on the ISO standard for pure Australian TTO can be found here.

Tea tree quality standards

Tea tree quality standards

What are the principal issues that impact tea tree oil and essential oil quality?
I have already touched on adulteration as a major issue and I believe this is the most significant quality threat we currently face as an industry. However, even pure TTO can be degraded over time due to poor distillation, storage and handling so producers, traders, manufacturers and end users need to be aware of these factors and minimize their effect. Exposure to light, high temperatures and atmospheric oxygen all lead to degradation of some of the components of TTO which can increase the incidence of skin irritation and sensitization.

On the ATTIA website in the section about packaging you can find a paper on the stability of pure Australian TTO which can also be downloaded here. This details the science behind storage and handling procedures. A quick summary:

  • ATTIA recommends that pure Australian TTO sold to the public should only be stored in small (up to 100 ml) dark glass bottles at temperatures not exceeding 25oC with a use by date of 2 years from the date of manufacture in unopened bottles.
  • Once opened these bottles should be stored in cool, dark conditions with the cap tightly sealed and discarded after 6 months if still unused.
  • For bulk storage, the ATTIA Code of Practice requires producers to use only stainless steel storage and transport vessels and to store the oil in cool, dark conditions with minimum exposure to air.
  • ATTIA recommends 3 years from filling as the use-by date for pure Australian TTO sold in correctly filled, purged (Nitrogen or Argon) and tightly sealed stainless steel drums stored at an ambient temperature not exceeding 25oC.

What do you see as the outstanding benefits of tea tree oil?
TTO has an enviable reputation for its antibacterial, antifungal, anti-inflammatory, anticancer and antiviral properties, which are all well supported scientifically. In 2013, TTO was exported from Australia to 43 countries, where its uses include cosmetic, industrial, and medicinal applications. It is interesting occasionally to see that in advertising for some new or emerging essential oils, comparison is most often made to the efficacy and safety of Australian TTO – reinforcing its position as a global leader.

Australian TTO is a natural product that contains more than 113 compounds and I believe that it is the synergistic effect of these compounds that makes it a true healing oil. Some components like terpinen-4-ol (the major constituent of TTO) have proven antimicrobial and antifungal properties on their own but there are all the other components which must assist and complement the terpinen-4-ol with factors such as skin penetration, bactericidal, fungicidal and anti-inflammatory activity.

Another outstanding benefit is its proven ability to control commonly occurring bacteria such as MRSA and VRSA that are rapidly becoming totally resistant to all conventional antibiotics, particularly in hospital environments where management of these infections is proving such a challenge to healthcare professionals. I believe that as we run out of control options, more and more health professionals will turn to products like TTO that have not only proven antimicrobial activity but also possess a natural complexity that makes development of bacterial or fungal resistance extremely unlikely.

Flowering Tea Tree copy

Melaleuca alternifolia in flower

What current or upcoming research projects is ATTIA involved in?
Over the last 20 years the Australian tea tree industry has been fortunate to enjoy a close partnership with the Australian Government’s Rural Industries Research and Development Corporation (RIRDC). RIRDC has co-funded much of the research, development and extension work done to develop our industry through a tree breeding program, agronomy advances, development of distillation techniques and safe storage and handling procedures for pure Australian TTO. In addition to these basic but vital tools RIRDC has co-funded much of the University based research into the safety, efficacy and uses of TTO resulting in more than 50 publications which are available for download from the TTO page on the RIRDC website here.

Currently ATTIA is developing a test for adulterated oil which we hope to have adopted by internationally recognized standards organizations in the near future. Called the Chiral Purity Test, this measures the ratios of the optical isomers of three compounds that occur in pure Australian TTO: terpinen-4-ol, α-terpineol and limonene. Each one of these compounds occurs in two forms, with specific ratios in TTO. Since we know what these ratios should be, any variation is a strong indicator that the product has been contaminated. Table 1 below illustrates 57 samples of Australian TTO sourced directly from plantations over five years (2007 – 2011) showing a consistent ratio (70:30) of the two terpinen-4-ol enantiomers (dextro and levo). Table 2 shows 47 samples of commercially available TTO sourced from around the globe as well as a sample of 98% pure terpinen-4-ol. Some have a significant deviation from the expected ratio for pure TTO, indicating adulteration. This demonstrates how easy it is to identify real TTO from adulterated material. As well as synthetic terpinen-4-ol, potential contaminants include industrial waste from ‘normalising’ pine, eucalyptus and other essential oils. ATTIA intends to use the test to “out” any offenders by reporting them to the relevant regulatory bodies in their jurisdictions.

Chiral Ratios for Terpinen-4-ol

Table 1

Terpinen-4-ol enantiomeric %

Table 2

ATTIA is also keenly following the progress of researchers at the University of Western Australia (UWA) who are investigating the anti-cancer potential of pure Australian TTO. A few years ago topical application of a very specific formulation containing pure Australian TTO as the active ingredient was shown to significantly reduce the viability of melanoma and mesothelioma cancer cells in vitro and since then studies of skin cancers in mice have confirmed its ability to reduce or resolve some types of skin cancers. Researchers believe this may be due to the stimulatory effect TTO has on the body’s own immune system. Much work remains to be done before this reaches proof-of-concept stage.

Researchers at UWA are also investigating the clinical activity of formulated products containing TTO for activity against acne-causing bacteria. This will eventually result in a pilot study using volunteers to measure the activity of the most promising formulations in a human population.

For the grower members of ATTIA there is continuing support for research into high yielding genotypes of M alternifolia through both a conventional breeding program and using cutting-edge technology to identify specific gene markers for high yield and disease resistance that occur in natural populations. These markers can be used to quickly and efficiently identify individuals with outstanding properties from existing wild populations for infusion into the ongoing conventional breeding program to increase genetic diversity and ensure sustainability. In an emerging area ATTIA and the Australian Government have recently commenced a joint study to investigate the use of biochar generated from spent leaf and inter-crop legume planting to reduce both carbon and nitrous oxide emissions. Increasing productivity and developing a low emission industry not only ensures survival of an industry that utilizes a native crop plant in a sustainable way but also improves the green credentials of an already clean and green industry.

Tea tree oil safety issues that have been raised in the past include skin sensitization, endocrine disruption and bacterial resistance. What is your take on these?
I want to address these separately as all three are critically important questions and need different answers.

Allergic reactions and skin sensitization
TTO that has been well stored since distillation is a safe, natural product and its efficacy and safety is well known and documented. There is absolutely no doubt that some people are allergic to pure Australian TTO in the same way that some people are allergic to peanuts, milk or wheat. This can manifest itself in many forms from reddening, irritation and itching of the skin through to blisters and burns. Whenever and wherever TTO is used for the first time a user should make sure that it is diluted in a carrier oil (eg jojoba) to 10% before trying a small drop on the soft skin of the inside of the forearm. Wait 24 hours, unless immediate signs of itching or swelling are noticed. If a reaction occurs, immediately wash the area with soap and water and discontinue use. It is worth mentioning that slight, transient irritation is sometimes seen in clinical trials, this may be considered acceptable, depending on the benefits. However, allergic reactions are never acceptable.

Immediate, strong allergic reactions to TTO are uncommon and have been estimated to occur in less than 0.5% of the population. Sensitization to TTO has also been well documented; this occurs where repeated exposure to a product increases the reaction to its application. This can happen with pure TTO, but it is more likely to occur where TTO has either been poorly stored, which increases the level of peroxides and other irritants through oxidation, or when the oil has been adulterated.

Endocrine disruption
This is a myth and is the one that get me the most upset. I often see reference in scientific articles, blogs and online comments that refer to a link between gynecomastia (man boobs) and lavender and tea tree oils and I have been battling the negative publicity that erupted when the original work by Henley et al was first published in the NEJM in 2007. The authors linked the use of personal care products containing lavender and/or tea tree oil to breast development in 3 prepubertal boys and then went on to “demonstrate” that the endocrine disruption was caused by the two essential oils using well trays in the laboratory. These 96 well trays, made of plastic, contain phthalates which are known endocrine disruptors and I know from personal experience that TTO is an excellent solvent and extracts phthalates from any unprotected plastic it comes in contact with very quickly and efficiently. I believe this is why Henley et al reported the estrogenic and anti-androgenic “activity” of TTO and lavender possibly without even realizing the truth. More here.

RT-pub-lavender-2If you look at this another way, at least 400,000 kg of pure Australian TTO is shipped annually and used by thousands of people in hundreds (or even thousands) of products as well as being applied as an undiluted oil for medical, cosmetic and aromatherapy uses every day. If TTO did indeed have any kind of estrogenic or other endocrine disruptive activity then surely gynecomastia or at least some other symptoms would have been seen in more than the three boys Henley et al looked at.

Bacterial resistance
The suggestion that exposure to sub-lethal levels of TTO induced resistance in bacteria was first reported in 2007 and again in 2008 by McMahon et al. In 2008, and again in subsequent years, researchers at the UWA TTO research group tried to replicate the work done by McMahon et al to no avail. Repeated attempts by scientists at the University of Western Australia (Hammer et al 2008, Hammer et al 2012, Thomsen et al 2013) failed to induce resistance to any antibiotics in any of the bacteria studied and led them to conclude in 2013 that “…there is no evidence to suggest that tea tree oil induces resistance to antimicrobial agents.” Unlike most antibiotics, which are usually single molecules, TTO contains more than 113 naturally-occurring molecules. The synergistic effect of these compounds makes it improbable that bacteria could develop resistance to TTO.

Do you feel that current legislation impacting tea tree oil is reasonable, and do you anticipate more restrictive legislation?
We live in a world where regulation plays a major part in the registration and use of any cosmetic or medicinal ingredient whether natural or synthetic in origin. Regulations are there to protect users from harm. Some products and chemicals are very harmful if used incorrectly or indiscriminately so we all have to accept that regulation is a fact of life; ATTIA’s approach is and always will be cooperative. Having said that it is worth pointing out that legislation varies far too much around the world and I would prefer a more uniform approach to this in the same way that many countries are now adopting and moving towards the UN’s Globally Harmonized System of Classification and Labeling of Chemicals (GHS). This makes legislation far easier to manage.

Restrictive legislation is frustrating to any essential oil industry simply because most of it is designed to work with a single molecule which is clear-cut, easy to identify and assay, and is usually also patentable. An essential oil is a variable complex of molecules that, like the human genome, belongs to all of us and at the same time to none of us – in other words a regulator’s nightmare! However there is also no doubt that these oils are efficacious, safe and widely used around the world in cosmetic and medicinal formulations so I believe that regulators need to look closely at these naturally occurring substances and create separate legislation for them. This is beginning to occur in some places, but while these are being developed essential oil industries are being forced to address two separate sets of legislation, which can be burdensome.

What are the principal challenges facing the tea tree oil industry?
In the short to medium term adulteration of a pure, natural product with byproducts and other waste from chemical factories is the foremost challenge facing our industry today. This practice is motivated purely by profit and relies totally on the safety, efficacy and reputation of pure Australian TTO while undercutting the market price often to the point where a farmer cannot safely and sustainably produce the original product. The result of this cheating is to devalue TTO as a viable product. Unless it is combated vigorously, this could lead to adulterated or wholly synthetic concoctions becoming the norm for customers buying or trading ‘tea tree oil’ resulting in a devalued and virtually useless substitute for the real thing. ATTIA is currently cooperating with scientists and regulators from around the world to develop a cheap, effective test that will allow a discerning manufacturer to detect some of the more common forms of adulteration. Once this has been adopted by internationally accepted Standards organizations such as ISO and BP it will make it harder and far more expensive for those who adulterate pure TTO to continue to dupe manufacturers and end-users for their own gain.

Young plantation_ GD copy

A young tea tree plantation

In the longer term, regulation is the other major challenge. Any natural substance varies slightly from year to year and from region to region but there are recognized standards in place that  manage this so why can’t regulators also deal with the natural variation in these substances more sympathetically? On top of this there is also the prohibitive cost of developing data required in some jurisdictions to enable registration as a medicine or cosmetic ingredient. This can run into millions of dollars which cannot be recouped over the period a patent is usually granted for a conventional single molecule pharmaceutical because no patent is available for TTO. Traditional or customary use patterns covering many decades by bona fide practitioners should be acceptable evidence of the safety and efficacy of natural products such as TTO.

How does ATTIA help support the tea tree oil industry?
As an industry association, ATTIA provides both a forum and a vehicle for members (and non-members where necessary) to promote and act on emerging trends and regulatory, market or other pressures and trends in a timely and cohesive manner. By maintaining a monitoring watch on these factors ATTIA has been well placed to prepare and submit dossiers to regulatory bodies that include the USA, Canada and Europe. These submissions are prepared to ensure that pure Australian TTO can continue to be used in these jurisdictions both as a cosmetic ingredient and as a traditional herbal remedy for its wide range of clinically supported uses.

ATTIA also provides advice, training and auditing services in the critical area of quality assurance or QA. This promotion of ATTIA’s voluntary Code of Practice helps ensure that all pure Australian TTO offered into both international and local markets is always in perfect condition with documented QA practices that can be seamlessly incorporated into a manufacturer’s own QA procedures.

Since its inception ATTIA has also invested considerable time, effort and funding on research into the production, distillation, storage safety, efficacy and uses of pure Australian TTO. Much of this work, supported by ATTIA member donations and Australian Government Research and Development Grants, has been done at the University of Western Australia where the TTO Research Group has published more than 50 papers in their primary areas of research which are the antimicrobial and anticancer properties of TTO. Many of these articles are used to support claims and as proof of concept for the safety, efficacy and uses of pure Australian TTO. More on UWA here.

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