Essential Oils and Allergens: What I Actually Do, and Why

I want to write about something I get asked a lot, and something I have thought about more than almost anything else in this business.

Bloom Skin exists because of my own skin. I had severe allergies and reactions, and nothing I was putting on my face or body was helping. Some of it was making things worse. I got tired of reading ingredient lists I could not make sense of, and tired of products marketed to sensitive skin that my sensitive skin did not agree with at all. So I started making my own, in my kitchen, badly at first, and then less badly, and then well enough that other people wanted them.

Given that story, you would think I would avoid essential oils entirely. Plenty of brands built on the same beginning do exactly that. I did not, and I want to explain why, and be completely straight with you about the trade off involved.

Let's start with the uncomfortable bit

Essential oils contain allergens. Not "some people might be sensitive to them" in a hand waving sort of way. Actual, documented, regulated allergens that appear on official lists precisely because they are known to cause allergic reactions in a proportion of people.

That is true of the ones in my products. It is true of lavender, geranium, sweet orange, frankincense, tea tree, and almost every other oil I work with. It is not a marketing problem to be worked around. It is just a fact of the material.

I would rather say that plainly on my own website than have you find it out somewhere else and wonder why I never mentioned it.

What "allergen" actually means, because the word gets used loosely

Three different things get muddled together constantly, and they are worth separating because they behave very differently.

Irritation is a direct effect. Something is too strong, or too acidic, or applied to broken skin, and the skin objects. It tends to happen quickly, it tends to happen to most people if the dose is high enough, and it usually settles once you stop. Anyone can be irritated by anything at a high enough concentration.

Sensitisation is your immune system learning to recognise a specific substance as a threat. This is the one that matters most, and the one people understand least. The first exposures might cause nothing at all. Your immune system is quietly building a file. Then at some point, months or years later, it decides that substance is an enemy, and from then on you react.

Allergic contact dermatitis is what happens after sensitisation. Redness, itching, sometimes blistering, usually appearing a day or two after contact rather than immediately, which is part of why people struggle to work out what caused it.

The important and slightly grim point about sensitisation is that it does not generally reverse. Once your immune system has decided that linalool is a problem, that is usually permanent, and the reaction can be triggered by very small amounts from then on. This is why I care so much about concentration. Every exposure to a sensitiser carries some risk of tipping someone over into sensitisation, and the higher the dose and the more repeated the exposure, the higher that risk climbs.

Why essential oils end up on allergen lists

An essential oil is not one substance. Lavender oil is a mixture of dozens of aromatic compounds, and the two that make up most of it are linalool and linalyl acetate. Citrus oils are heavy in limonene. Rose geranium is high in citronellol and geraniol. These individual compounds are the allergens, not the oil as an abstract thing.

Under the UK Cosmetics Regulation, there is a list of fragrance allergens that must be named separately on the ingredients list once they pass a certain level. That threshold is 0.001% in a leave on product like a balm, and 0.01% in a rinse off product like a soap bar. Those are tiny numbers, which is deliberate. The point of the list is to let someone who already knows they react to geraniol scan a label and make a decision without having to ask anyone.

So when you see linalool, limonene, citronellol, geraniol or citral at the end of one of my ingredient lists, that is not a hidden synthetic that crept in. Those are the naturally occurring components of the oils listed above them, declared because the law quite reasonably says they should be.

Worth knowing if you follow this sort of thing: the EU expanded its list from 26 declared allergens to 82 under Regulation 2023/1545, with deadlines of 31 July 2026 for new products and 31 July 2028 for existing stock. Great Britain has not adopted that change, so UK products currently still work to the original 26. The expectation across the industry is that the UK will consult on aligning at some point. I mention it because if you compare a UK label to an EU one over the next couple of years, the EU one may name more allergens, and that difference is regulatory rather than a difference in what is actually in the bottle.

The part almost nobody talks about: oxidation

This is the section I most wanted to write, because it is genuinely useful and it rarely comes up in natural skincare marketing.

Limonene and linalool in their fresh state are fairly weak sensitisers. The problem is what happens when they meet air. Both oxidise, and the oxidation products, specifically the hydroperoxides, are considerably more potent sensitisers than the original compounds. In dermatology clinics where patients with suspected contact dermatitis are patch tested, positive reactions to hydroperoxides of limonene and linalool turn up at meaningful rates, often somewhere in the region of five to twelve percent depending on the population studied.

There is a practical consequence of this that I think everyone should know, whatever brand you buy. A freshly opened product may be completely fine, while an identical product that has been open in a warm bathroom for a year may cause a reaction. Same ingredients on the label. Different chemistry inside. If you have ever had a product suddenly stop agreeing with you after months of happy use, this is one plausible explanation.

The other consequence is for how things are made and stored. Heat, light, air and time all push oxidation along. That shapes decisions like batch size, packaging, and whether an antioxidant goes in.

What I actually do about it

Here is where I land, and I want to be precise about what these choices do and do not achieve.

I do not formulate up to the ceiling. There are maximum levels for how much of a given fragrance compound can go into a product, and my assessor would not sign anything off that exceeded them, so staying within the limits is not really a claim worth making. Any legally sold cosmetic has done that. The decision that actually belongs to me is where I sit underneath them. Those limits mark the point where risk becomes unacceptable, not the point where it becomes comfortable, and there is a lot of room below. A product does not need to be loud to work, and in a leave on balm that stays on your skin all day, restraint matters more than it does in something you rinse off in ninety seconds.

I blend across a lot of oils rather than leaning on one or two. People sometimes assume I do this purely for the scent, and honestly the scent is part of it, because layered blends smell more interesting than single notes. But it also spreads the load. Five oils at low levels means no single allergenic compound is sitting at a high concentration, even though the total aromatic content is the same. If you are sensitised to one specific compound, a lower amount of it is a better position to be in than a higher amount.

Every product goes through a formal safety assessment. Mine are done by an external assessor who checks the formulation against the regulations, including allergen levels and declaration requirements. That is a legal requirement for selling cosmetics in the UK, not something I do voluntarily, but it is worth knowing that it exists and that any product you buy here should have had one.

I make in small batches. Partly because I have no choice, given I make everything myself. But it does mean stock moves quickly and nothing sits around for years oxidising before it reaches you.

I include antioxidants where the formula calls for it. Vitamin E in the oil based products is not just there as a skin ingredient. It slows down the oxidation of the oils themselves.

Now the honest part. None of this makes my products allergen free. It cannot. What it does is reduce the dose and reduce the chance of the sensitising oxidation products building up. Lower risk is a real and worthwhile thing. It is not the same as no risk, and I am not going to pretend otherwise.

Natural is not a safety category

I make natural products. I believe in what I make. And I still think "natural" has become one of the least useful words in this industry.

Plants produce their aromatic compounds as chemical defences. Deterring insects and fungi is the entire evolutionary point of most of them. They are not designed with human skin in mind, and the idea that something is gentle because it grew in a field does not survive contact with the evidence. Some of the most reactive things you can put on skin are entirely natural.

What natural means in my range is a short ingredient list, raw materials I understand, minimal processing, and no filler. Those are things I value. They are not, on their own, a promise about how your particular skin will respond, and I try never to let one slide into the other.

What the evidence says, and where it runs out

I own a reference encyclopaedia of essential oils that I use constantly, and I read around this properly. Which means I am also aware of how thin some of the evidence is.

I find it useful to sort claims into three tiers, and to be clear with myself about which tier I am standing in.

Tier one, reasonably well studied. Tea tree oil is probably the strongest example. It has genuine antimicrobial activity demonstrated in laboratory work, and there have been randomised controlled trials of tea tree gels for mild to moderate acne. Even here, systematic reviews conclude the evidence is promising rather than conclusive, and call for more and better trials. That is what tier one actually looks like for essential oils, and it is more modest than most brands imply.

Tier two, traditional and long standing use. A great deal of essential oil knowledge sits here. Generations of people have used chamomile on irritated skin and calendula on grazes, and there is real value in that accumulated experience. It is not the same kind of evidence as a controlled trial, and it should not be dressed up as one, but it is not nothing either.

Tier three, my own experience and what customers tell me. This is where a lot of my genuine enthusiasm lives. I love how my skin feels after using my balms. Customers write to me about their skin. That is meaningful to me and it drives what I make. It is also the weakest form of evidence there is, because I am not a neutral observer of my own products and neither is someone who chose to buy them.

There is a further point I keep coming back to. Absence of evidence is not evidence of absence. A great many essential oil constituents have simply never been studied properly in the specific ways that would answer the questions people ask, because that research is expensive and there is no patent at the end of it to pay for it. Research keeps growing, and things we cannot currently support may well be supported in ten years.

But I try to be careful with that thought, because it can quietly turn into a get out of jail card. "It has not been studied yet" is a description of the state of research. It is not a reason to believe something is true in the meantime. If I catch myself using it to prop up a claim I could not otherwise make, that is the moment to stop and just say I do not know.

Why I hold myself to that line

I am a registered nurse. I do not work in a clinical role at Bloom Skin, I work as a formulator, and I do not want that registration to be used as a sales tool. It should not be the reason you trust a product.

What it does mean is that I am bound by a professional code that applies to me outside of working hours as much as inside them, and one of its central principles is that information I give people should be evidence based. So my registration functions as a constraint rather than a credential here. It is the reason I will not tell you an oil treats a condition when what I actually have is a lab study and some enthusiasm. It is the reason I only mention improvements in skin conditions when a customer has described them in their own words, rather than claiming them in mine.

It also means there are things I cannot do from behind a screen. I cannot diagnose you. I cannot look at a photograph and tell you what your rash is. If something on your skin is painful, spreading, weeping, infected, or simply not going away, that is a conversation for your GP, a pharmacist, or a dermatologist, not for a skincare company. I would much rather lose a sale than have someone treat a persistent skin problem with a balm when they needed to be seen.

Who my products may not be right for

Saying this out loud costs me sales and I think it is the right thing to do.

If you have a diagnosed fragrance allergy, my range may not suit you. Particularly if patch testing has shown you react to fragrance mix I or II, balsam of Peru, or specifically to the hydroperoxides of limonene or linalool. Low concentrations are still concentrations, and a sensitised immune system can respond to very little. Every product page on this site carries the full ingredient list, so you can go through the range and check for the compound you react to before you buy anything. If you are not sure, do not gamble on it.

If you have severe, active, broken or weeping eczema, that is not the moment to introduce a new fragranced product. Compromised skin absorbs more and reacts more readily. Get the flare settled with whatever your clinician has advised, then think about what to use day to day.

Please patch test. A small amount on the inner forearm, left alone, checked over the following forty eight hours or so. It is not a perfect test, since it will not predict sensitisation that develops later, but it will catch an existing reaction before you have applied something to your whole face.

For very young babies, plain unfragranced products are the sensible default, and I would say the same about anyone else's range as well as my own.

And one thing I want to be firm about: I do not describe my products as hypoallergenic, and I would treat that word with suspicion wherever you see it. It has no fixed legal definition and it tells you nothing reliable about whether a specific product will suit a specific person.

So why use them at all

Because after all of the above, I still choose to, and I want to give you the real reason rather than a dressed up one.

I love how they smell. Not as a nice extra, but as a genuine part of what the products are for. The scent of a blend I have spent weeks getting right, on my skin at the end of a long day, does something for me that an unscented balm does not. Smell reaches the parts of the brain involved in memory and emotion by a very direct route, and while I am wary of overclaiming what any specific oil does to mood, the general connection between scent and how you feel is not in dispute by anyone who has walked past a bakery.

I also like how my skin feels, and I like the small ritual of it. Applying a balm properly is thirty seconds of paying attention to yourself, which is not a medical claim and does not need to be one.

And some of these materials do have properties beyond scent, within the limits I set out above. I am not going to overstate that. I am not going to understate it either.

What I can promise you is this. I will keep the levels low. I will keep declaring every allergen on the label. I will keep telling you when something might not suit you. And when I do not know something, I will say so rather than reaching for a phrase that sounds like knowledge.

If you have questions about anything in a specific product, or you want to know exactly what is in something before you try it, message me. I answer these myself and I do not mind the detail at all. It is my favourite part.

You can see the full range here, ingredient lists and all.