Are essential oils in candles toxic? Let's clear the air!
The myth that essential oils are toxic when burned in candles comes from a mix of misinterpretations, fear-based marketing, and a lack of scientific nuance. Here's a breakdown of how this rumour started and spread:
Misunderstanding "Toxic" vs. "Irritating"
Some essential oils can produce irritants when exposed to extremely high, uncontrolled heat (e.g., open flame or poorly formulated candles). But in a properly made candle, the oils are gently heated and vaporised, not combusted.
What’s true: Burning anything can produce volatile organic compounds (VOCs).
What’s false: That all essential oils are inherently toxic when used in candles. There is no evidence that properly formulated candles using essential oils pose a health risk under normal use.
Confusion with Incense and Smoke
People often confuse burning incense or diffuser smoke, which does combust materials, with the way candles diffuse essential oils via heat only. Essential oils in a candle are heated and volatilised, not burned in the flame itself (unless the candle is made incorrectly or the wick is too hot). This would course exactly the same issue fronfragracne also.
Fragrance Oil Industry Pushback
Some sellers of synthetic fragrance oils have promoted the idea that essential oils are unsafe in candles to defend their products’ superior scent throw, consistency, and cost-effectiveness. These marketing narratives have seeped into DIY communities heavily with many repeating the same narrative and spreading this marketing misinformation sadly.
Lack of Research = Assumption of Danger
Because essential oils are natural and complex, and because there's little industry-standard testing on their use in candles (in fragrance also) , many people default to "better safe than sorry." That’s often spun into "essential oils are dangerous when heated", despite a lack of evidence for this claim in properly made candles.
Reality Check:
Essential oils do break down at high heat, and some (like citrus) may fade quickly.
But this is not the same as producing harmful or toxic fumes at candle-safe temperatures.
Moderation, proper wick sizing, and clean-burning wax are key for both essential oils and fragrance for a safe candle.
Let's stop spreading misinformation.
The rumour started from a mix of overcautious advice, confusion with combustion, and competitive marketing and has been widely spread by DIY groups. There’s no actual credible evidence as of this date that essential oils are toxic in well-made candles.