Citrus oils and the sun — what is worth remembering

This is one of the few safety rules with essential oils worth knowing by heart — because it concerns the oils people reach for most often, and because the consequences only show up after the fact.

Where the problem comes from

Oils pressed from citrus peel contain compounds from the furanocoumarin group (the best known is bergapten). Under UV light these can cause a phototoxic reaction on the skin — discolouration or irritation resembling sunburn, often in exactly the shape of the place where the oil was applied.

This concerns oils applied to the skin. Dispersing them in a diffuser is not a problem here.

Which oils this concerns

The ones most often named are bergamot, lemon, lime and grapefruit. Two details are worth noting:

• —The method of extraction matters — steam-distilled oils usually contain no furanocoumarins, unlike cold-pressed ones.
• —Some citrus oils, sweet orange for example, are generally considered non-phototoxic — but checking the label is always safer than relying on memory.

The practical rule

The manufacturer advises avoiding direct sun and sunbeds for around 12 hours after applying such an oil to the skin. In practice, the simplest approach:

• —Citrus on the skin — in the evening, not before heading to the beach.
• —During the day — in the diffuser, where the restriction does not apply.
• —Areas usually covered by clothing are safer than the hands, the neckline and the face.

If it has already happened

Discolouration after a phototoxic reaction can persist for weeks. There is no home trick that speeds it up — where the skin is clearly irritated, the right address is a doctor or a dermatologist, not another oil.

It is always worth reading the label of the particular product too. A phototoxicity warning is on it when it genuinely applies.