I'm sure we've all been through the hanging trees or the odour masking fresheners, the most common complaint we heard is that they give headaches or water eyes. But why?
What's Inside a Synthetic Car Air Freshener?
Conventional car air fresheners — the hanging cards, vent clips, and gel cans you find at gas stations — are almost entirely synthetic. The scent doesn't come from real flowers, real pine, or real citrus. It comes from a proprietary chemical blend that manufacturers are legally not required to fully disclose, often listed on the label simply as "fragrance."
Inside that word, there can be dozens of undisclosed compounds. Research has identified several concerning ones commonly found in air fresheners:
- VOCs (Volatile Organic Compounds) — synthetic chemicals that vaporize at room temperature and stay suspended in the air you breathe
- Phthalates — chemical plasticizers used to make fragrances last longer, linked to hormone disruption
- Formaldehyde — a known carcinogen that can form when air freshener chemicals react with the air
- Benzene and toluene — industrial solvents with documented health risks
The EPA has linked VOC exposure to headaches, nausea, dizziness, respiratory irritation, and in cases of prolonged exposure, damage to the liver, kidneys, and central nervous system.
So we decided to swap out most of the chemicals and use a natural form of fragrance instead. Essential oil
So What Exactly Is an Essential Oil?
Essential oils are the exact opposite of synthetic fragrance. They are pure, concentrated extracts taken directly from plants — the leaves, flowers, bark, roots, rinds, or seeds — with no synthetic chemicals added.
The extraction process has been used for thousands of years. The earliest evidence of aromatic oils dates to 4500 BCE in Egypt, where they were used in cosmetics, with the art of crafting essential oils well-documented in China and India around 3,000 BCE.
Today the most common method is steam distillation — steam is passed through the plant material, releasing its aromatic compounds into a vapor, which is then cooled back into a liquid. What you're left with is a highly concentrated oil that carries the full aromatic and biological profile of the original plant. No synthetic additives. No undisclosed chemicals.
For citrus oils, cold pressing is used instead — the rind is pierced and pressed, releasing the oil without any heat at all.
The key difference is simple: essential oils are derived from nature. Synthetic fragrances are manufactured in a lab. One ingredient list is a plant. The other is a chemical formula that nobody is required to show you.
Why Your Car Makes It Worse
Your car is a small, enclosed space. On a hot day, heat accelerates the rate at which chemicals off-gas from synthetic fresheners — a process called thermal off-gassing. Studies have found that VOC concentrations inside cars using conventional air fresheners can be several times higher than outdoor levels.
If you spend an hour commuting every day, that exposure adds up fast.