Dear Science - Are You Sure About The Test Results on Those Allergens?

I've written about this before a few years ago, and have been researching it on and off ever since, because quite frankly, there are some things that





What's worse, I keep hitting walls in my research. So I'll just throw the question out there – again.

The LisaLise Theory

I believe science might very well have gotten some of it wrong when they were testing essential oils for possible allergens.

Dead wrong.

You Dare to Question Science, Lise?!

Yes, I dare to question science. I question science because I am not fully convinced it took everything into account while it went about doing what was doing.

I question science because of things that continue to not add up.

Why does this matter?

Because some of science's test results became the basis from which policy-makers made their decisions, rules, policies and laws.

If science did happen to get it wrong, then there are findings that need to be re-examined and tests that need to be redone.

Possible Allergens

Let's take a brief look at some ingredients – in particular the ones on the European "list of 26 possible allergens in cosmetics ingredients that must by law be declared on every cosmetics label".

Many of these possible allergens are components of essential oils, for example:
  • linalool
  • limonene
  • geraniol
  • benzyl alcohol
  • citronellol
  • cinnamal
  • eugenol
  • d-limonene
And there are more, but you get the drift.

What Doesn't Add Up

For years, I've pondered why a person such as myself (who reacts very strongly to synthetic perfumes: itchiness, rash, headaches etc) never experiences any such reaction when exposed to the numerous 'possible allergens' present in essential oils?

You: You're an oddball, Lise. Probably the only person on the planet to react like that.


Several members of my family react the same. Many of my clients react the same. Friends, acquaintances, people I meet at dinner parties, events, lectures, etc react the same. Although I've never conducted an actual survey, over the years I've both met and learned of many people who react strongly to synthetic perfume but not essential oils.

I have a theory about that: I suspect lab testing equipment is the culprit.

Essential Oils and Plastics Mix - For Real

While it is common knowledge to people who work extensively with essential oils that essential oils will react with plastic, I'm not entirely convinced science was aware of that bit of information as they performed their tests on essential oils.

Let's take a look at lab equipment. Test trays and tubes can be made made of any of the following
  • PETG (Polyethylene terephtalate)
  • Polyethylene
  • Polystyrene
  • Polypropolyne

Every one of these materials are plastics.

Polystyrene, for example, is safe for use in food products, but is not recyclable. Described as 'generally non-biodegradable' and 'considered an environmental issue', polystyrene is resistant to acids and bases but is easily dissolved by many hydrocarbon solvents and organic solvents which dissolve the polymer.

See where I'm going with this?

You: Don't think you're so smart, Lise. They probably didn't even use plastic test tubes. They probably used petri dishes made of borosilicate glass.

I had that thought too, so I researched petri dishes.

I have not been able to find any petri dishes in borosilicate glass or even 'just' glass. Petri dishes are all made of polystyrene these days.

Which brings me to the next question: when did it become 'these days'?

These Days vs Test Days

It would appear most lab testing equipment is produced in China 'these days' and it has been impossible for me to find out what came before. What were petri dishes or test tubes made of when the original tests on essential oils were conducted?

You tell me. I can't find any info on this.

I can't even find information on when were the original tests were conducted.

It could have been as far back as 1920.

Or 1960.

Maybe it was only a few years ago.

But even if it was a mere 5 years ago, there doesn't seem to be any information on lab equipment available. Apparently, the history of lab testing equipment doesn't have anyones interest. There is no website, no museum, no lab-test-equipment-lovers-club anywhere.

If you happen to have a link or info, please do leave a comment!

Until Science Speaks Up...

I cannot help but wonder if science may have made a big fat boo-boo when they tested essential oils by placing them in plastic equipment and thereby getting tainted results.

If that is indeed the case, then essential oil components might not even belong on the list of 26 possible allergens.

So, I ask again: Science, are you 100% sure about those test results?

Do Tell

Do you have a reaction to synthetic perfumes but not to essential oils? Please share!


Production Process Contamination of Citrus Essential Oils by Plastic Materials
Polystyrene (wikipedia)
Polystyrene degradation along coastlines of northeast Pacific Ocean
PETG (wikipedia)
Difference between PET and PET-G
Polyethylene Terephalate May Yield Endocrine Disruptors
PET Resin Association
Study on Leaching of phtalates from polyethylene terephlate bottles into mineral water
Borosilicate Glass (wikipedia)
Kids Science Fun: Watch citrus essential oils eat through styrofoam
USP Class Explained
SCCS Final Opinion on Fragrance Allergens in Cosmetics Products available (2012)
Health and Consumer Scientific Committee list of 26 components
Aromatherapy Science - a Guide for Healthcare Professionals - Chapter 7 safety issues
Constituents of Essential Oils - AromaWeb

Previous Related Posts on This Subject

Essential Oils and Endocrine Disruptors
26 reasons these fruits may cause allergies
Essential Oils and Plastic 


Unknown said…
Interesting blog post Lise! I had the pleasure of attending a talk by the Director of Science from IFRA two years ago. In that talk he basically admitted that there had been only one population study looking at the reaction to sensitisers in essential oils and that it was already quite old. Nonetheless, policy makers decided that sensitivity to fragrance allergens is increasing and that they should therefore force the listing of more than the 26. This discussion has been ongoing for many years now but we're no closer to having a clear answer on it. I wrote this article after attending his talk:

The other interesting point is that I've seen Robert Tisserand mention that he thinks the actual population level reaction to essential oil sensitisers might be as much as a factor of ten lower than the 'official' 2% estimates. There is a LOT of research required for this topic and of course this doesn't make life any easier for people who do have a genuine fragrance allergen sensitivity. Patch tests are currently done on about 40 allergens, so what will people have to endure when they increase the list to 100+ sensitisers?!
LisaLise said…
Thank Lorraine for this insightful comment! I am now on my way to check out your link. Thanks for your input on this!
Unknown said…
Hi Lise,

I'm with you here. I'm so sensitive that I can't use any shop-bought shampoos nor conditioners as they turn my scalp burning bright red! I have to bypass the (synthetic) perfume area of department stores as the fumes go straight to my chest and make me cough. I couldn't use any shop-bought face or body creams either as they always gave me an instant itchy rash. That is partly why I turned to making my own shampoos, conditioners, hair tamers and of course face and body creams and various other products. (I've even formulated a cream my son can use on his psoriasis that calms it, after his having tried so many shop-bought ones that didn't work and usually aggravated it.) I liberally use essential oils in all my products (even my son's) and I make my own perfumes with them and I've never had any problems. I diffuse them too. My daughter, who's allergic to just about everything, can use my products with essential oils in - and loves them! Of course this is just my experience but it adds to the picture.

I very much appreciate all the information you've made available to us and I love it that you dare to question science!

Heather x
Unknown said…
You make some excellent points Lise! One person's reaction can be totally different to another's. I, unfortunately, am one of the "lucky" few who has very negative reactions to using some essential oils and "natural" ingredients. In the beginning of my DIY journey, I tried lavender essential oil, sandalwood essential oil, beeswax, and honey in different topical applications - all with very bad consequences. My throat closed up and I spent lots of money being treated for severe allergic reaction. I have learned to be especially careful with any ingredient considered "natural" because, for me, assuming something is safe has proven to be quite disastrous. I also don't discount an ingredient just because it's synthetic, because some work better for me than a "natural" alternative. While I do understand the point you are trying to make, encouraging people in the opinion that natural is safer or better is not always true for everybody. Believe me, how I wish it was!! It would make DIying so much easier!
Cynnara said…
Interesting article. However, there are people who react to either or both. This was the most recent pubmed study on essential oil allergy reactions. I'm not saying you might not have a point, however, you need to learn the leech rate, the length of the tests conducted, time the material is kept in the tubes and more. Until those pieces of information are correlated as well, it is speculation. That said, you could request a study to be conducted by a research facility if you have access to one. Then perhaps these things can be set aside and better testing conducted. There will always be more to learn. And as my science always quoted, "Arsenic is natural, but I don't recommend it to be taken internally or externally."
Signe said…
First I need to say that science is not absolutely 100% right about anything - every knowledge is relative, and no research can observe every possible variables.

Secondly, even if I am like Lise myself (I can tolerate essential oils much better than synthetical perfums), I know some people cannot tolerate neither of them. For example, if you are really allergic for mold, you might tolerate no scents at all. We are all different and we might react differently to same things.
LisaLise said…
@Heather - Thanks for your input! I think you and I could go shopping together - we would avoid the same places! :D

@Belinda - Oh dear! It sounds like you have the worst of it not tolerating either or! You are quite right in that some synthetic ingredients are better tolerated by the super sensitive. It sounds like you have learned how to deal with everything in the best way possible. Good for you!

@Signe - You are absolutely on point. We are indeed all different which makes it a huge challenge for formulators and developers of medicine. Thanks for your input!
LisaLise said…
@Cynnara - thanks for the link and input. If you read Lorraines comment above, it seems I am not the only one claiming there is not enough information available on past tests to know about reliability. I would love to request a study done but I imagine the first question would be *who's paying for it?*. I am unfortunately unable to carry the cost of such a study. :)
K said…
I don't have a link to share with you but I would just like to say that I am one of the lucky people who has SEVERE reactions to both synthetic perfumes and essential oils.

There are some other products however that are not "scented" where it is better for me to have a synthetic version than a natural version because I have so many allergies and sensitivities (soy and coconut are two that are in a lot of "natural" products) but it is hard to find natural hair products for example without essential oils and they do cause serious rashes for me as well as migraines etc. Just my experience.
LisaLise said…
Hello K - thank you for sharing your experience