Sunshine and Phototoxic Essential Oils

As mentioned in our previous writings, essential oils are wonderful to help support the mind, body and spirit, but they are not without contraindications. We need to be aware of some of the chemistry of essential oils, as that can help us understand whether the oil is safe to use or not. You’ve probably heard things like “all citrus oils are phototoxic essential oils”, or that “oxygen is not good for your oils”, but what do these statements mean, are they true, and how do we find out more about it?  

What Do We Mean By Phototoxic Essential Oils

Some essential oils contain chemical constituents that react with ultraviolet light. These can irritate the skin causing rashes, burns and make it very vulnerable to sunburn. They are molecules, called furanocoumarins, (FC) are primarily found in citrus oils. These usually (but not always) happen when an oil has been made from pressing the oil from a citrus peel, rather than distilling it. 

Phototoxic Essential Oils

This list is a reliable one that says, if you buy them, know that they are most certainly going to be phototoxic essential oils. 

So, we might say that all citruses are phototoxic essential oils, and indeed that is quite a safe way to look at it, if you are a beginner. But if we explore it further, actually there are a number of non-phototoxic essential oils that are derived from citrus plants. 

Oils Made From Citruses That Are Not Phototoxic Essential Oils

  • Bergamot FCF Essential Oil (FCF Has the Bergaptene/Furanocoumarins Removed)
  • Bergamot Essential Oil (Steam Distilled)
  • Blood Orange Essential Oil (Cold Pressed or Steam Distilled)
  • Lemon Essential Oil (Steam Distilled)
  • Lime Essential Oil (Steam Distilled)
  • Mandarin Essential Oil (Cold Pressed or Steam Distilled)
  • Sweet Orange Essential Oil (Cold Pressed or Steam Distilled)
  • Petitgrain Essential Oil
  • Tangerine Essential Oil (Cold Pressed or Steam Distilled)
  • Yuzu Essential Oil (Cold Pressed or Steam Distilled)

Are Phototoxic Essential Oils Always Phototoxic


To make things even more complicated, it’s not necessarily that there are furocoumarins in a particular oil but also how but also how much of them there are. It is the quantity that tends to be the problem, so sometimes an oil may or may not be phototoxic based on the chemistry of this year’s crop. 

Luckily, these are not really commonly used essential oils. 

Sometimes Phototoxic Essential Oils

  • Clementine Essential Oil (Cold Pressed)
  • Angelica Root Absolute
  • Angelica Root CO2
  • Celery Leaf Essential Oil
  • Celery Seed Absolute
  • Cumin Seed Absolute
  • Cumin Seed CO2
  • Parsnip Essential Oil

Please note that this is not a complete list of all phototoxic essential oils. For a full and complete list, please refer to Essential Oil Safety by Tisserand and Young. 

Using Phototoxic Essential Oils Safely

How you use phototoxic essential oils  also needs to be taken into account.  Sometimes, it doesn’t even matter if they are phototoxic essential oils because the way you use it might render that obsolete. 

Tisserand states that "There is generally no phototoxic risk if the oils are used in a product that is either not applied to the body or is washed off the skin, such as shampoo, bath preparation or soap. However, essential oils can adhere to the skin if used in a sauna or steam inhalation. There is no risk if the skin to which the oils are applied is covered in such a way as to prevent UV rays from reaching them."

Tisserand also recommends that "skin treated with phototoxic oils at levels higher than those maximum use levels, should not be exposed to UV light for 12-18 hours.

In practical terms, that means using the oils in the evening before you go to bed, or ensuring your skin remains covered throughout the day if you have used them in the morning. 

Likewise, the risk of phototoxicity is negated if you use very small dilutions of the oil. Bergamot, for example, does not carry a risk of phototoxicity at dilutions below 0.4% . So, one drop in a tablespoon of carrier oil will work much better than just a teaspoon. 

Oils can also be perfectly stable, but then run the risk of photosensitivity as the oil begins to oxidize. 

How Does Oxidation Cause Phototoxic Essential Oils

Oxidation is the chemical reaction that takes place when a substance comes into contact with oxygen, heat, light or another oxidizing substance. This chemical reaction degrades the essential oils’ aromatic and therapeutic properties. Strangely, various chemical groups degrade differently. Again, we worry about citruses here, since their lovely uplifting natures come from monoterpenes. Monoterpenes are tiny things that degrade very quickly leading to oxidization. If you use oxidized oils, it can result in irritation or sensitization. This means the oils can leave your skin with rashes, burns, or blisters.

To reduce oxidation, we advise you to keep your oils stored in cool, dark places, away from direct sunlight. Ensure the lids are kept on tightly, and make sure you don’t store them in plastic containers.

In summing up, using phototoxic essential oils can lead to skin burns. Not storing your oils away from heat, light and oxygen can lead them to degrade more quickly and make them not as effective. This can also lead to them causing skin irritations as well.


Tisserand, R and Young, R (2014). Essential Oil Safety, Second Edition. Churchill Livingstone Elsevier, UK.

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