Which Essential Oils are Phototoxic, in other words, sun sensitizing?

I generally tell people to stay away from any CITRUS essential oils in skin preparations that will be used during the day. But I can be more specific!

Beware of
Especially phototoxic:
* Bergamot essential oil
* Cold-pressed lime essential oil

Also phototoxic:
Grapefruit essential oil
Bitter orange essential oil
Cold-pressed lemon essential oil

The above are not equally photosensitizing. It takes 24 times as much grapefruit essential oil to be as phototoxic as 1 drop of bergamot.

In 30mL of carrier oil, cream or lotion, here's the maximum number of drops you could use before the whole preparation will be phototoxic:

1 drop of bergamot
4 drops lime CP (cold pressed)
8 drops bitter orange (Citrus aurantium)
12 drops lemon CP (cold pressed)
24 drops grapefruit

Cold Pressed means that the rind or zest of the citrus fruit has been squeezed to release the natural oil. Technically, this is an expelled oil rather an a essential oil. The bottle should be marked CP. Essential oil are specifically steam- or hydro- distilled.

Five-Fold: Means that the material has been distilled five times over. Through distillation, terpenes are partially removed from the oil thus giving it a slightly stronger scent, extending the shelf-life, and reducing the sun sensitizing potential.

Bergaptene-Free Bergamot: Means that the bergaptene content that causes photosensitivity has been removed. This allows bergamot to be used in skin and hair care formulations without concern for phototoxicity after exposure to the sun.

You'll notice contradictions online, and even in the image below against what I've written. These differences can be due to misunderstandings of cold pressed versus steam distilled, or steam distilled versus 5 fold (meaning the same material has been distilled 5 times over), due to different species with similar common names (orange bitter Citrus aurantium IS, but sweet orange Citrus sinensis IS NOT), or perhaps due to different readings from different batches.

According to the research reported in Tisserand and Young’s book, Essential Oil Safety, these citrus essential oils are not phototoxic:

Mandarin essential oil
Wild orange/Sweet orange essential oil
Tangerine essential oil
Steam-distilled lemon essential oil
Steam-distilled lime essential oil

Although there are a few, pretty sketchy and rare essential oils, that are NOT citrus, but that ARE phototoxic, lemongrass is not one of them. It can be, however, irritating to skin, so I only use it in scar removal preparations.

If you don't want to remember all of that, simply avoid CITRUS essential oils used as natural fragrances or active ingredients, in anything you leave on your skin. We do use "5-Fold" and "Sun Safe" versions of citrus essential oils that are safe in skin preparations and perfumes.

SO OKAY:
soaps
shampoos
body washes
night lotions, creams serums or balms, when carefully washed in the morning

NOT OKAY:
sunscreens
moisturizers
balms
salves
serums
lotions
creams
perfumes

Stay safe!