Dermal Limits for Essential Oil Safety

What Are Essential Oils? - Essential oils are natural aromatic compounds and volatile liquids extracted from the seeds, roots, bark, stems, leaves, flowers, resins, and other parts of plants. These valuable liquids are most commonly obtained from plants through distillation — often by using steam. They can also be expressed mechanically or cold-pressed, as is the case with citrus oils extracted from peels. When solvent extraction is used, the end product is an absolute that contains both essential oils and other plant constituents. This oil is not a true essential oil, but it is often used by the aromatherapist. The chemical makeup of essential oils is highly complex and may consist of hundreds of distinct chemical compounds.

Dermal Limits for Essential Oil Safety

Essential Oils - The concentration (dermal limits) used incorrectly formulated skin care products are low enough not to cause a reaction, however, if you are experiencing very sensitive skin and or have a compromised barrier essential oils are best avoided. Some Essential oils do contain allergens and it is compulsory for manufacturers to list them - examples include: 

  • Benzyl alcohol
  • Benzyl salicylate
  • Cinnamyl alcohol
  • Cinnamal
  • Citral
  • Coumarin
  • Eugenol
  • Geraniol
  • Isoeugenol
  • Anisyl alcohol
  • Benzyl benzoate
  • Benzyl cinnamate
  • Citronellol
  • Farnesol
  • Limonene
  • Linalool

    Safety Guidelines - For the use of Essential Oils are common sense, EU Cosmetic Regulations expect manufacturers to comply with the guidelines set by the IFRA. (International Fragrance Association) Essential Oils contain chemical compounds which, for some people can cause a skin reaction.

    Each essential oil has different recommended usage rates depending on the body area to be used and whether it is a leave on or wash off product.
    Dermal limits: A general guide - Facial Care leave-on products not more than 1% of the total product formulation. 


    Haptens - Essential oils contain a large number of small molecules (called haptens) that can bind to proteins present in the body. Upon binding, these complexes (called haptenated proteins) will initiate an immune system response and cause allergic reactions. An example of how exposure to haptens can cause an immune response is the well-known allergic reaction to poison ivy caused by the hapten urushiol. Penicillin is another example of a hapten that can cause anaphylaxis.

    Extremely Potent - Essential Oils are extremely potent botanical extracts and need only be used in small amounts to be of therapeutic benefit. Only 2% of the population is thought to experience reactions to essential oil compounds.

    Irritation - Caused by a chemical compound, the skin will react as soon as it is exposed to them, the concentration of the chemical irritant will dictate the severity of the skin reaction experienced. 

    Sensitisation - This is a type of allergic reaction that you may not notice upon immediate exposure to the chemical compound, further exposure to the compound will cause an inflammatory response by your immune system causing further sensitisation. In other words, this has been acquired over time and by repeated exposure and can happen to anyone. It’s a never-ending cycle, too - once you’ve had a reaction to a product, your skin’s uppermost layer (stratum corneum) is compromised, giving way to the potential for even more problems.

    Phototoxicity (PT) - Also known as photosensitivity, is a skin reaction that occurs in the presence of Ultra Violet (UV) light. Certain compounds found in essential oils are capable of absorbing energy from UV light much more effectively than skin. The application of the Essential Oil itself will not cause PT unless the skin is exposed to the sun or another UV light source. PT agents are known as 'Bergapten' or 'furocoumarins' these are polycyclic molecules whose structure gives them the ability to absorb ultraviolet photons, store them for a while and then realise them in a 'burst' onto the skin.

      Allergies // food or seasonalIt has also been observed that those with allergies (food or seasonal), chronic skin conditions, or autoimmune and autoinflammatory conditions are more prone to sensitivity, even pure oils of the highest quality. Those with known allergies, food sensitivities, autoinflammatory or autoimmune disorders, and skin conditions (eczema, psoriasis, etc.) are more likely to develop skin sensitivities to essential oils. Essential oils that aromatherapy texts suggest may cause skin sensitivity in those with allergies to include:
      Basil // Cedarwood // German Chamomile // Clary Sage // Clove // Fennel // Ginger // Juniper // Lemon // Lemongrass // Orange // Peppermint // Pine // Melaleuca // Thyme // Ylang Ylang. 

        SensitisersEach Essential Oil may contain different levels of known sensitisers, the onus is on the manufacturer to find out which compounds are present in each essential oil and then calculate the total in the formula they are creating. These potential sensitisers must then be listed on the product label if they are present in concentrations over 0.001% (cosmetic leave on products) for example a moisturiser.

        Skin Reactions - Are dose-dependent and vary according to the concentration of oil applied to the skin. Essential Oils should never be applied undiluted to the skin for that reason especially not on compromised skin with a 'Disturbed Barrier'. Skin reactions can and do vary between individuals.

        Disturbed Barrier - Studies suggest that sensitive skin is the result of the impaired barrier function of the stratum corneum (SC), this is the very outer layer of the epidermis, therefore, the body's first defense against the environment, sun damage, penetration of foreign matter toxins and microorganisms. A functioning SC is a key to healthy skin. 

        CONCLUSION - always read the label! look at the full ingredient list and check for allergens (known potential skin sensitisers) Pure, unadulterated, high quality (certified organic) therapeutic essential oil(s) incorporated into correctly formulated personal care products offer beneficial plant compounds. Always do a patch test with any new personal care product to check for any reactions (inside of forearm). Pregnant women should do their due diligence and research which essential oils are considered safe to use during pregnancy and or nursing. (Good news - many are considered safe.) for example Turmeric and Chamomile (Roman and German).

        Until next time..

        be human, be kind, be you









        • Essential Oil Dermal Limits - Formula Botanica (2015)

        • Book // Essential Oil Safety: A Guide for Health Care Professionals 2nd Edition by Robert Tisserand, Rodney Young. (2014)
        • IFRA Guidelines

        • Book // The Complete Guide to Aromatherapy Second Edition S. Batteglia (2007) Johnson, Dr. Scott A.. Evidence-Based Essential Oil Therapy: The Ultimate Guide to the Therapeutic and Clinical Application of Essential Oils 


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