Phototoxic Essential Oils – which ones to avoid when out in the sun

Phototoxic Essential Oils

If you use essential oils topically, you'll want to pay close attention to this post. Using certain essential oils topically with sun exposure (or in tanning beds) can damage the skin. This kind of phototoxic damage to the skin can be permanent.

What is Photosensitization?

According to Essential Oil Safety, photosensitization (also known as photocontact dermatitis) is, “a reaction to a substance applied to the skin that occurs only in the presence of UV light in the UVA range, and it may be either phototoxic or photoallergenic.

Phototoxic reactions are the most common, and are the focus of this post. Photoallergy is typically reserved for non-essential oil chemicals, although sandalwood and garlic are potential photoallergens.

What are the signs of phototoxicity?

Furanocoumarin-containing essential oils react to UV light and can cause an inflammatory reaction in the skin. Visible reactions typically peak up to three days after initial UV exposure. The visible signs can last for weeks, and might be one or more of the following:

  • severe redness (sunburn)
  • darkening of skin
  • edema (swelling)
  • in some cases, blistering

Signs of Phototoxicity

Essential oils containing furanocoumarins

Some essential oils which contain furanocoumarins and are to be used with caution are:

  • Angelica Root (Angelica archangelica)
  • Bergamot* (Citrus bergamia, Citrus aurantium)
  • Grapefruit (Citrus x paradisi)
  • Lemon – cold pressed (Citrus x limon, Citrus limonum)
  • Lime* – cold pressed (Citrus x aurantifolia, Citrus x latifolia)
  • Mandarin Leaf (Citrus reticulata, Citrus nobilis)
  • Orange, Bitter (Citrus x aurantium)
  • Rue* (Ruta graveolens, Ruta montana)

*essential oils which may lead to photocarcinogenesis

How to avoid photosensitization

Robert Tisserand writes in Essential Oil Safetyskin treated with phototoxic oils at levels higher than those maximum use levels, should not be exposed to UV light for 12-18 hours.” He goes on to say essential oils can produce a phototoxic reaction “12 hours after application” and how one application “continued to produce phototoxic reactions for 36 hours.”

The easiest way to avoid photosensitization is to not apply a furanocoumarin-containing essential oil to the skin at all.

Covering up any skin to which phototoxic essential oils have been applied can help to prevent a phototoxic reaction. However, thin fabrics, such as some tee shirts, may not provide adequate protection.

Phototoxic essential oils can still be used topically on the skin, even with exposure to UV light, as long as they are safely diluted (keep reading for safe dilution guidelines).


Essential oils that are safe to use in the sun

Many people write off all citrus essential oils as being phototoxic, but there are several that are safe to use, including steam-distilled versions. Although furanocoumarins are present in cold pressed versions, the molecules are not volatile and remain behind during steam distillation. Sun-safe essential oils include:

  • Bergamot – steam distilled – bergapten-free/furanocoumarin-free* (Citrus bergamia, Citrus aurantium)
  • Lemon -steam distilled (Citrus x limon, Citrus limonum)
  • Lime – steam distilled (Citrus x aurantifolia, Citrus x latifolia)
  • Mandarin – cold pressed (Citrus reticulata)
  • Orange, Sweet – cold pressed (Citrus sinensis, Citrus aurantium var. sinensis)
  • Tangerine – cold pressed (Citrus reticulata, Citrus nobilis, Citrus tangerine)

*I bought mine here: Florihana bergapten-free Bergamot on Tropical Traditions.


Safe dilution guidelines for potentially phototoxic essential oils

In order to use phototoxic essential oils without an adverse reaction, they must be safely diluted.

Here is a table outlining safe dilution levels. Heeding these dilution levels will protect you from suffering from a phototoxic reaction.

For more information on how to dilute, read: Diluting Essential Oils Safely – safe dilution guidelines for all ages.

Safe dilution guidelines for potentially phototoxic essential oils

Essential oil name and Latin name Safe dilution level Drops per oz.
Angelica Root (Angelica archangelica) 0.8% 4.8
Bergamot (Citrus bergamia, Citrus aurantium) 0.4% 2.4
Grapefruit (Citrus x paradisi) 4% 24
Lemon – cold pressed (Citrus x limon, Citrus limonum) 2% 12
Lime – cold pressed (Citrus x aurantifolia, Citrus x latifolia) 0.7% 4.2
Mandarin Leaf (Citrus reticulata, Citrus nobilis) 0.17% 1.02
Orange, Bitter (Citrus x aurantium) 1.25% 7.5
Rue (Ruta graveolens, Ruta montana) 0.15% .9

Safe dilution guidelines for potentially phototoxic essential ioils

Do you have a question or comment? Leave a message here, post in the FB group, or e-mail me.

Lea Harris is a Certified Clinical Aromatherapist Scholar's Program graduate from Aromahead Institute. This website, and its sister website, LearningAboutEOs, is home to educational advice and information about using essential oils safely. Lea founded and runs the Using Essential Oils Safely facebook group, with hundreds of new members joining each week. Lea is the author of The TRUTH About Essential Oil Safety, and the creator of Safe Essential Oil Labels and the UEOS App. You can find FREE classes here: Free Essential Oil Classes.

Lea received her herbalist certification through The Herbal Academy of New England. Lea is a contributing writer for Natural Herbal Living magazine, and blogs about herbs and natural living on her website, Nourishing Treasures.

Lea is Professional level member of the Alliance of International Aromatherapists.

Businesses, groups, and individuals can hire Lea to consult on safety, product formulation, and more on her website Lea Harris CCA.



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