If you've shopped for candles online recently, you've probably seen the term "non-toxic" everywhere. Soy candles are marketed as "non-toxic alternatives" to paraffin. Beeswax is advertised as "naturally non-toxic." Entire brands have built their identity around being "the non-toxic candle company."
But here's a question worth asking: What does "non-toxic" actually mean when it comes to candles? And where did this language come from?
The answer traces back to a single conference presentation in 2009—a study that was never peer-reviewed, yet fundamentally reshaped how we talk about candle safety.
The Study That Started It All
In August 2009, two researchers from South Carolina State University presented findings at the American Chemical Society meeting in Washington, D.C. The two had tested paraffin and soy candles by burning them in a small enclosed box (8” x 8” x 26”) and analyzing the emissions.
Their conclusion? Paraffin candles released detectable amounts of toluene and benzene—two chemicals known to be toxic at high concentrations. Soy candles, according to their findings, did not release detectable amounts of the same chemicals.
Despite the research never having been peer-reviewed, the University issued an attention-grabbing news release. With that, the study made headlines immediately Major media outlets ran stories with titles about toxic chemicals in everyday candles. Some of the headlines included “Are candles making you sick?”, “Romantic candles could cause cancer, scientists say”, “Candle-lit dinners can lead to cancer”. The news’ message was clear and alarming: paraffin candles were releasing cancer-causing compounds into your home.
From Science to Soundbite
Here's where things get interesting. The study's nuanced findings—that trace amounts of certain compounds were detected under specific test conditions—quickly became simplified in media coverage and consumer consciousness.
"Paraffin releases benzene and toluene" became "paraffin candles are toxic."
By contrast, "soy candles did not release detectable amounts of these compounds in our test" became "soy candles are non-toxic."
The language shift was subtle but profound. Instead of discussing concentrations, exposure levels, and context, the conversation became binary: toxic versus non-toxic.
What the Headlines Didn't Mention
As the "toxic candle" story spread, several important details got lost:
The study was never peer-reviewed. It was presented at a conference but never published in a scientific journal where other researchers could scrutinize the methodology and conclusions. As of the writing of this blog post (3/4/2026) there is no publicly available copy of the abstract of the presentation to provide any details about it.
It was funded by the USDA's soy research program. The title of the grant that funded the research was “Soybean Candles for Healthy Life and Well Being”, indicating a distinct bias even before the research was conducted. This doesn't automatically invalidate the findings, but it does represent a clear conflict of interest.
Context about concentrations. While in many of the articles it did mention that the level of chemicals emitted by paraffin candles were not known to be a health hazard, that message seemed to be overwritten by the sensationalized headlines.
The Marketing Gold Rush
Following the 2009 publicity, "non-toxic candle" became one of the most valuable phrases in candle marketing. Brands realized that positioning themselves as the "non-toxic alternative" was an incredibly effective sales strategy.
The problem? "Non-toxic" has no actual definition in the candle industry let alone any agreed upon levels of any particular emissions that would be considered toxic. There's no regulatory body that certifies candles as non-toxic. It's marketing language, not a meaningful safety designation. Yet you will see it everywhere.
What "Non-Toxic" Really Means (Or Doesn't)
When a candle is labeled "non-toxic," what does that actually tell you?
- Is it referring to a specific set of toxic chemicals or any possible toxic chemical?
- Non-toxic at what level of exposure?
- Non-toxic compared to what baseline?
- Non-toxic when not burning or under what burning conditions?
- For which populations (adults, children, people with respiratory conditions)?
The term answers none of these questions. It's a marketing claim that sounds scientific but provides no meaningful information about actual safety or emissions.
What Actually Matters
Rather than looking for "non-toxic" labels, here's what you should care about:
Wax quality and purity: Well-refined wax of any type—whether paraffin, soy, beeswax, or coconut—burns more cleanly than poorly processed alternatives. The refinement and purity matter more than the source material [1].
Absence of unnecessary additives: Synthetic fragrances and dyes introduce additional chemicals into the combustion process. These additives are a far more significant source of indoor air quality concerns than the base wax itself [2].
Proper wick sizing: A well-designed candle with an appropriately sized wick maintains efficient combustion, minimizing incomplete burning and emissions.
Ventilation during use: Any combustion process produces emissions. Normal air circulation helps prevent accumulation.
The Real Takeaway
The 2009 study wasn't necessarily wrong. The research apparently detected certain compounds in some paraffin candles under specific test conditions. But the way those findings were translated into consumer messaging created a very misleading narrative.
Candles aren't binary, either toxic or non-toxic. They exist on a spectrum of quality, with multiple factors affecting how cleanly they burn and what they emit. Well-made candles with quality ingredients and proper design can burn cleanly and safely, regardless of whether they're made from paraffin, soy, beeswax, or other materials.
The "non-toxic" language that now dominates candle marketing is a direct legacy of that single 2009 conference presentation. It's a compelling marketing narrative, but it's not a meaningful safety designation.
Actual peer-reviewed and published scientific research has actually shown little difference in emissions between paraffin and natural wax candles. What does make a significant difference in emissions is the addition of fragrances [2].
When you're choosing candles, look beyond the marketing buzzwords. Ask about actual ingredients, manufacturing processes, and product quality testing. Choose unscented options to eliminate the largest variable (added fragrances). Look for transparency from manufacturers about what's actually in their products.
And remember: the absence of a "non-toxic" label doesn't mean a candle is dangerous, and the presence of that label doesn't guarantee anything about safety or quality.
For a deeper dive into what actually affects candle emissions and quality, read our companion posts: The Science Behind Your Candle's Glow and Understanding Candle Quality: What Makes Some Candles Burn Cleaner Than Others
- Derudi, M., Gelosa, S., et. al. (2014). Emission of air pollutants from burning candles with different composition in indoor environments. Environmental Science and Pollution Research, 21(6), 4320–4330. https://doi.org/10.1007/s11356-013-2394-2
- Salthammer, T., Gu, J., Wientzek, S., et. al. (2021). Measurement and evaluation of gaseous and particulate emissions from burning scented and unscented candles. Environment International, 155, 106590. https://doi.org/10.1016/j.envint.2021.106590