Now that you’re thinking about it, you might expect that the answer is yes. But as it turns out, the answer isn’t so black and white. Here’s why—plus what you need to know before buying your next bottle of oil.
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It’s all about the production method
First, the good news: Pesticides aren’t as big of an issue for many essential oils as you might expect, says Kathi Keville, Director of the American Herb Association and author of The Aromatherapy Garden.
Whether an essential oil has pesticide residues has a lot to do with the way it was produced. For starters, many of the plants that are commonly used for essential oils—like rosemary, citronella, thyme, lavender, and clove—are so effective at repelling bugs that they’re not vulnerable to most garden pests. “They’re innately pesticides themselves, so they aren’t often sprayed,” Keville says. (Here's how to grow fragrant lavender anywhere.)
Of course, not all essential oil plants are naturally pest-resistant. And there’s always the chance for cross-contamination, where pesticides from other crops make their way onto essential oil plants via wind or water. But even if a plant is sprayed with pesticides, those pesticides won’t often make it into your bottle of essential oil. That’s because most essential oils are extracted from plants through distillation, a process where steam breaks down plant material to remove its volatile compounds. The essential oil-rich water vapor is cooled and condensed into water. Since oil and water don’t mix, the essential oils pool on the water’s surface, where they’re skimmed off.
As a result, the chances are low that any pesticides that were on the plant to begin with would make it into the essential oil. “Steam can only carry tiny, tiny particles, and essential oil molecules happen to be some of the smallest molecules in nature,” Keville says. But the molecules of most pesticides are much larger. Too large, in fact, to be carried by steam, she explains. There’s also the fact that some pesticides don’t do well in extreme temperatures, so they could start to break down in the steamy conditions of a distiller.
Related: 5 Essential Oils You Should Always Have In Your Medicine Cabinet
But there are exceptions to the rule. Namely, citrus essential oils like orange, lemon, grapefruit, and bergamot. The reasons are two-fold: First, citrus fruits aren’t naturally pest-resistant, so conventional crops are almost always sprayed. And second, citrus essential oils are almost always cold-pressed—where the oils are squeezed out of the plant instead of distilled through heat. That process is significantly more likely to allow pesticides on the peel of citrus fruits to end up in essential oils, Keville says.
Research backs this up. In a German analysis looking at nearly 600 samples of 28 different essential oils, 64% of distilled essential oils showed no sign of pesticide residues. Among those that did, only a tiny amount—just .17%--exceeded exposure levels considered safe by European health organizations. Cold-pressed oils fared worse—only 34% were found to be free of pesticide residues. And the pesticide residues of cold-pressed oils were more likely to exceed safe exposure levels.
What to look for when buying
Seeking out organic options for citrus essential oils or other cold-pressed oils is definitely a smart idea. (Some good organic citrus options available on Amazon: Aetos Certified Organic Lemon Essential Oil; and Aura Cacia Certified Organic lemon, bergamot, and sweet orange essential oils.)
And it may be worth going the organic route for distilled oils, too. Even though it’s considerably less likely, there’s a chance that they could still harbor pesticide residues. In either case, buying organic gives you peace of mind that the oil you’re buying is clean. Sure, it’s true that many non-organic essential oil producers (especially small-batch ones) may follow organic growing practices but can’t afford the pricey organic certification process.
Related: 6 Times You Should Never Use Essential Oils
But unless you can ask a conventional producer about their methods, there’s no way of knowing for sure whether a conventional essential oil crop was sprayed with pesticides. “Organic certification will clear that up,” Keville explains. And if you care about seeking out truly safe, natural remedies, that peace of mind is worth the higher price.