Are Scented Candles Toxic? What to Look For (And What to Avoid)

It's a question I never thought to ask until I started asking it professionally.

As a nurse, I spent years thinking carefully about what goes into bodies, but at home, I was lighting candles without a second thought.... whatever was on sale. I wasn't connecting what I burned in my living room to what I preached about clean air and body safety at work.

When I started researching candles seriously — the kind of research that keeps you up past midnight reading ingredient studies — I found something that genuinely surprised me. Most of the candles we light without thinking contain ingredients we would never consciously choose to bring into our homes.

Here's what I found, and what it means for you.

The Short Answer

Yes. Some scented candles can release chemicals that are worth taking seriously, particularly with regular, long-term exposure in poorly ventilated spaces. The good news: it's not hard to avoid them once you know what to look for.

The Ingredient Problems Worth Knowing About

Paraffin Wax

Paraffin is a petroleum byproduct. It's what most cheap and mid-range candles are made from because it's inexpensive and holds fragrance well. When burned, paraffin can release compounds including toluene and benzene, both of which are classified as volatile organic compounds (VOCs).

To be clear: a single candle burned occasionally in a ventilated room is unlikely to cause measurable harm. But if you're someone who burns candles regularly, the cumulative exposure picture looks different. And in smaller spaces like bathrooms and bedrooms, it matters more.

What to look for instead: Coconut wax, soy wax, or beeswax. These are plant or natural-derived alternatives that burn more cleanly and produce significantly fewer VOCs. At Upsensed, we use a coconut/soy wax blend specifically because it outperforms 100% soy on scent throw and burns more evenly than either alternative.

Phthalates

This one is less discussed and more important.

Phthalates in candles are plasticizing agents used to help fragrances bind to wax and extend their scent throw. Phthalates are endocrine disruptors, meaning they can interfere with hormonal function, and they're on the restricted or banned list in the EU under several cosmetic safety directives.

They're not banned in the US.

A lot of mass-market candles use phthalate-containing fragrance oils because they're cheaper and more stable than phthalate-free alternatives. The label won't tell you. You have to ask, or buy from a brand that's already answered.

What to look for instead: Brands that explicitly state their fragrance oils are phthalate-free and can tell you where they're sourced. This should not be a hard question for a candle brand to answer. If it is, that's information.

Cotton Wicks With Metal Cores

Lead wicks were banned in the US in 2003, so you don't need to worry about those. But some cotton wicks still contain metal cores, typically zinc or tin, to help them stand upright. When burned, these can release trace metal particulates into the air. Look for candles that specify 100% cotton or wooden wicks.

How to Read a Candle Label

Here's a practical checklist for evaluating any candle before you buy:

Wax: Is it named specifically? Coconut, soy, beeswax, and apricot are good signals. "Proprietary blend" or "soy blend" with no further detail is not.

Fragrance: Does the brand state phthalate-free? Fragrance-oil sourcing transparency is a mark of a brand that's thought carefully about what they're making.

Wick: Cotton or wood. Avoid anything labeled "metal core."

Certifications: Not required, but brands that voluntarily submit to third-party safety testing are worth noting. Look for IFRA compliance on fragrance ingredients.

Not sure how to compare what you're finding? The breakdown in luxury candles vs. regular candles covers exactly why ingredient quality tends to differ between mass-market and small-batch options — and what those differences actually mean for how a candle burns.

Why I Built Upsensed Around This

When I decided to start making candles, I already knew I couldn't use paraffin. I already knew phthalate-free wasn't optional for me — it was the baseline. As a nurse, I'd spent too long thinking about cumulative body burden and environmental exposure to make something I couldn't stand behind completely.

What I didn't expect was how much better a clean-burning candle could perform. Our coconut apricot wax throws scent further, burns longer, and produces a cleaner, brighter flame than other candles I'd burned for years.

Clean doesn't mean compromised. It turns out it means the opposite.

The Bottom Line

You don't need to be alarmed about the candle you lit last Tuesday. But if candles are part of your regular ritual then what's inside them is worth knowing.

The standard isn't hard to meet. It just requires brands that care enough to meet it.