When We Looked Closer at Fragrance

When We Looked Closer at Fragrance

What We Learned About Air, Health & the Hidden Complexity of Scent

It didn’t begin with a rejection of fragrance. It began with a question.

We loved candles. We loved atmosphere. We loved ritual. But we realized we had never really asked:

What actually happens to fragrance when it’s burned?

So we looked closer.

And what we found wasn’t dramatic. It was simply more complex than we expected.

Fire Changes Chemistry

A candle flame can exceed 1,000°C.

At that temperature, fragrance oils - whether synthetic or essential - do not remain chemically unchanged. They are heated, partially combusted, and transformed.

Peer-reviewed indoor air studies have measured emissions from fragranced candles during combustion.

This does not mean lighting a candle automatically creates unsafe exposure.

But it does confirm something important:

  • Fragrance does not simply “disappear.”
  • It becomes part of indoor air chemistry.

What Changes When a Fragranced Candle Burns?

Stage What happens Why it matters in real homes
Wax melts Solid wax becomes liquid. A normal part of how a candle works.
Vapour forms Liquid wax turns into vapour near the wick. That vapour is what fuels the flame.
Combustion Vapour burns at high temperature (often >1,000°C). Heat can alter fragrance compounds (synthetic or essential).
Emissions VOCs and fine particles may be released during burning (see Uhde & Salthammer, 2007; Derudi et al., 2012). These become part of indoor air, especially in enclosed or poorly ventilated spaces.
Secondary reactions Some fragrance components (e.g., terpenes) can react indoors and form secondary pollutants (see Singer et al., 2006; Nazaroff & Weschler, 2004). What’s in the air can continue to change after the candle is lit, depending on ventilation and conditions.

Note: Real-world impact varies with room size, ventilation, burn time, and total fragrance load.

Indoor Air Is Not Neutral

We often think of pollution as something outside.

But environmental health research consistently shows that indoor air can contain higher concentrations of certain pollutants than outdoor air - especially in enclosed, poorly ventilated environments.

In modern UK homes:

  • Windows are closed during colder months.
  • Insulation is high.
  • Air exchange is lower.

When fragrance burns in smaller rooms, compounds can accumulate depending on ventilation, burn duration, and room size.

This affects everyone in the space.

Adults.
Children - who inhale more air relative to body weight.
Pets - who process scent and airborne compounds differently.

The air is shared.

“Natural” Does Not Mean Unchanged

Many fragranced candles rely on essential oils rich in terpenes such as limonene.

Indoor air chemistry research (Nazaroff & Weschler, 2004) shows that terpenes can react with ozone indoors to form secondary pollutants including formaldehyde and ultrafine particles. https://doi.org/10.1111/j.1600-0668.2004.00275.x

This isn’t an argument against plants.
It’s an acknowledgement of chemistry.

Combustion transforms molecules.
Oxidation changes structure.

Nature is not static when exposed to flame.

The Cumulative Question

Candles are not the only source of airborne compounds indoors.

  • Cleaning sprays.
  • Laundry detergents.
  • Air fresheners.
  • Cooking.
  • Furniture materials.

Exposure is cumulative.

The question we kept returning to was simple: If fragrance is not essential to the function of a candle, why introduce additional airborne variables at all? Especially in smaller, enclosed living spaces.

The Environmental Layer

Fragrance compounds don’t just stay indoors.

Volatile compounds can contribute to secondary pollutant formation outdoors, and synthetic fragrance ingredients can persist in wastewater systems.

The environmental footprint of fragrance chemistry is complex - and ongoing.

Again, this doesn’t demand panic.

But it does invite intention.

What We Chose

We didn’t decide fragrance was inherently harmful.

We decided simplicity felt responsible.

We wanted:

  • The warmth.
  • The ritual.
  • The glow.

Without adding additional fragrance chemistry into the air we breathe every day.

So we made our candles scent-free.

Not as a trend.

As a considered choice.

If You Love Fragrance

This isn’t an argument for elimination.

If you choose fragranced candles, a few simple considerations can reduce indoor load:

  • Burn in well-ventilated spaces
  • Keep burn times moderate in smaller rooms
  • Trim wicks to maintain a steady flame
  • Be mindful of other fragranced products used in the same space

Indoor air is cumulative.

Small adjustments can meaningfully reduce overall exposure.

When We Looked Closer

When we looked closer, we didn’t find alarm.

We found evidence that combustion changes fragrance chemistry.
We found measurable emissions documented in indoor air studies.
We found that ventilation, room size, and cumulative exposure all matter.

For us, that was enough to make a simple decision.

If fragrance isn’t essential, we prefer not to add it.

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