Essential Oils to Avoid

This page provides important information on essential oil safety. In particular, which essential oils to avoid for everyone and which to avoid for people with special needs, such as epilepsy. It also explains some safety issues concerning essential oil use, such as phototoxicity.

Just because essential oils are natural doesn't mean that they are all safe to use.

There are some oils that should not be used at all because they contain components that may cause liver or kidney damage; some may even be carcinogenic (cancer causing).

Then there are some essential oils that should be used with care and in very small amounts because they contain certain chemical components that may be skin irritating, or may cause toxicity if used in a high percentage.

If you are unsure as to whether an oil is safe to use or not, ask someone knowledgeable in essential oils, such as a certified aromatherapist. There are a lot of websites with information on essential oils - some are created by qualified aromatherapists (like this one :) and the information is well-researched and accurate; however, there are also some sites that give information and advice that is questionable and sometimes downright dangerous.  So please do use prudence and care.

Note that as there are so many essential oils, the lists below are not exhaustive. Remember, when in doubt, ask!

Essential Oils to Avoid and Safety Issues

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Essential Oils to Avoid At All Costs

EOs to Avoid Here is a list of essential oils that have serious health concerns and should NOT be used by anyone:

  • Bitter Almond (Amygdalus communis var. amara)
  • Boldo (Peumus boldus)
  • Buchu (Agothosma betulina or Barosma betulina)
  • Calamus (Acorus calamus)
  • Horseradish (Cochlearia armoracia)
  • Mugwort (Artemisia vulgaris)
  • Mustard (Brassica nigra)
  • Pennyroyal (Mentha pulegium)
  • Rue (Ruta graveolens)
  • Sage (Salvia officinalis)
  • Sassafras (Sassafras albidum)
  • Tansy (Tanacetum vulgare)
  • Thuja (Thuja occidentalis)
  • Wormwood (Artemisia absinthium)

Essential Oils to Avoid for People with Epilepsy

​In addition to the oils listed above, people with epilepsy or prone to seizures should also avoid these oils:

  • Birch (Betula lenta)
  • Feverfew (Tanacetum parthenium)
  • Genipi (Artemisia genepi)
  • Ho Leaf (ct camphor) (Cinnamomum camphor ct. camphor)
  • Hyssop (ct pinocamphone) (Hyssopus Officinalis ct. pinocamphone)
  • Lanyana (Artemisia afra)
  • Rosemary (Rosmarinus officinalis)
  • Spanish Lavender (Lavandula stoechas)
  • Spike Lavender (Lavandula latifolia)
  • Western Red Cedar (Thuja plicata)
  • Wintergreen (Gaultheria fragrantissima)
  • Yarrow (Achillea nobilis)

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Essential Oils that Can Cause Phototoxicity

In aromatherapy, it is important to remember that some essential oils are “phototoxic”, which means that if you apply such oils to the skin, and then the skin is exposed to ultraviolet ray, you will risk getting severe sunburns from the UV ray.

Quite a few citrus oils are phototoxic.

Whether you will get burned depends on how much phototoxic oil you use and how long you are then exposed to the sun.

Phototoxic reactions can occur up to 18 hours after the oil is applied to the skin and then exposed to UV light. Signs of reactions include:

  • Severe sunburn and blistering.
  • Reddening of the skin.
  • In serious cases, swelling and discoloration of the skin may also occur.

Does that mean we can never use such oils on our skin?

Fortunately, we can still use such oils if we understand how to use them properly! For example:

  • Avoid sunlight or tanning bed after applying phototoxic oils to the skin.
  • If you need to go outside for a long period of time after applying such oils to the skin, cover up! For example, wear a scarf around the neck (if oils are applied on the neck), wear long-sleeves if oils are applied to the arms, etc.

Be really careful if you are blending several phototoxic oils together, because the risk of phototoxicity increases. For example, if you use Bergamot, Lemon and Grapefruit, the phototoxic reaction will increase if the site of the application is exposed to the sun or a tanning light for any length of time.

Common Phototoxic Essential Oils

Here is a list of phototoxic oils and the safe dilution levels that can be used:

Essential Oil Max. % Drops/oz
Bergamot (Citrus bergamia) (cold pressed) 0.4% 1-2
Lemon (Citrus limon) (cold pressed) 2% 12
Lime (Citrus aurantifolia) (cold pressed) 0.7% 4
Grapefruit (Citrus paradisi) (cold pressed) 4% 24
Bitter Orange (Citrus aurantium) (cold pressed) 1.25% 7-8
Mandarin Leaf (Citrus reticulata, Citrus nobilis) 0.17% 1
Angelica Root (Angelica archangelica) 0.8% 4-5
Rue (Ruta graveolens) 0.15% 1

Note that not ALL citrus oils are phototoxic. These citrus oils are not:

  • Lime (distilled)
  • Lemon (distilled)
  • Sweet Orange (cold pressed)
  • Mandarin (cold pressed)
  • Tangelo (cold pressed)
  • Tangerine (cold pressed)

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Using Essential Oils Safely


Please refer to this page for more information regarding how to dilute essential oils.

People with Special Needs

Seniors & People with Chronic Illnesses

Use essential oils with care on people over 65 or those whose immune systems are compromised or who have chronic diseases.  Blends should be diluted to 1%.  Some oils are contraindicated with certain medication; therefore, check each oil very carefully and, when in doubt, ask a certified aromatherapist!

People who are prone to allergic reactions or asthma attacks should use essential oils with extreme caution.


Please refer to this page for more information regarding which essential oils to avoid.

Children and Babies

Please see our pages on aromatherapy for babies and small children for more information.

Other Safety Issues

If you are going to use an essential oil or blend for the first time, it is advisable to do a patch test first to see if there is any sensitivity or allergic reaction.

If an essential oil or blend causes skin irritation, wash it off right away with soap and water, and then apply carrier oil to the affected area.

Many essential oils smell very good - so good that children (or pets!) may want to taste the oils, so be sure to keep all oils out of the reach of children and pets.  Essential oils can be poisonous if swallowed.

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Tisserand, R. & Young, R. (2013).  Essential Oil Safety: A Guide for Health Care Professionals. 2nd Edition. Churchill Livingstone.