Toxic and Phototoxic Essential Oils

Eucalyptus essential oil
Andres Victorero / Getty Images

Essential oils are amazing products of our natural world. The oils of aromatic plants have been used for centuries for both their smell and their medicinal applications. But just because something is natural doesn't mean it's good for you. Sometimes a little bit of something may be good...but a lot can be harmful. Aspirin, or vitamins, or even the sun can be harmful when taken in excess.

Essential oils are no different. There are a number of essential oils that have chemical components that, while completely natural, need to be used with caution.

Toxicity in essential oils comes in two forms:

  1. Phototoxicity — these essential oils become toxic when exposed to direct sunlight. These oils are fine in candles, but shouldn't be used in any sort of application where the essential oil will stay on your skin and be exposed to the sun. Using these oils in soap is o.k. because it is rinsed off, but using them in a balm or lotion is not recommended because the essential oils stay on your skin.
  2. Toxicity — at certain levels, these essential oils will make you sick, or hurt you in some way — whether in the light or not. Several of them can be used safely in soap making and candle making, but you need to exercise caution and moderation, which usually means using them in very low concentrations. Many of them just need to be left alone.

Below are some of the essential oils that must be used with varying levels of caution:

Phototoxic Essential Oils

  • Angelica root
  • Bergamot (unless it's specified as "bergaptene-free")
  • Cassia
  • Cumin
  • Ginger
  • Lemon
  • Lime (just the cold expressed oil, not the steam distilled)
  • Lovage
  • Mandarin (possibly)
  • Orange (unless it's a "folded" orange — luckily, most are)
  • Verbena

Potentially Toxic or Problematic Essential Oils — Use With Caution

  • Anise (star)
  • Aniseed
  • Bay laurel
  • Bay (West Indian)
  • Calamintha
  • Camphor (white)
  • Cassia
  • Cedarwood (Virginian)
  • Cinnamon (leaf)
  • Clove (bud)
  • Coriander
  • Eucalyptus
  • Fennel (sweet)
  • Hops
  • Hyssop
  • Juniper
  • Nutmeg
  • Parsley
  • Pepper (black)
  • Sage (Spanish)
  • Tagetes
  • Tarragon
  • Thyme (white)
  • Turmeric
  • Valerian

Note: Just because they're on this list doesn't mean you can't use these oils in your soap making or candle making. It just means you need to do your research beforehand and know exactly what the characteristics and cautions of that particular oil is. For example, eucalyptus essential oil is generally known to be non-toxic and non-irritating when diluted properly, but it can be very toxic if taken internally. Cinnamon, clove, cassia and many of the "spice" essential oils, can be used safely in soap making but can be irritating if used in too high a concentration, or to people with sensitive skin. Most any essential oil, whether it's on this list or not, can be irritating if used in too high of a concentration or placed straight on the skin.

The key here, as with any of the other potentially hazardous chemicals or ingredients we use in our candles and soap making, is to know and understand each of the ingredients that you are using in your products...and be careful!

Another note: This list is not comprehensive of every single essential oil that may cause harm — and I'm not a doctor or intending to give any medical advice. It is for general information and reference only.