Are the scented candles cancirogenic?

Are Scented Candles Carcinogenic? A Scientific Assessment of Health Risks

The growing popularity of scented candles for creating ambiance and pleasant aromas in homes has raised questions about their potential health impacts. Based on current scientific research, there is evidence suggesting that certain types of scented candles may release compounds with carcinogenic properties. However, cancer risk depends on candle composition, usage patterns, and ventilation.

Chemical Emissions from Scented Candles

When scented candles burn, they release various compounds into the air, some of which have been identified as potentially harmful:

Volatile Organic Compounds (VOCs)

Scented candles emit volatile organic compounds both when lit and unlit, though their profiles differ significantly between these states. When burned, they release formaldehyde, acetaldehyde, and other hazardous VOCs. A study analyzing emissions from six different candle types found formaldehyde concentrations as high as 2098 ppb in strawberry-scented candles, 1022 ppb in cotton-scented candles, and 925 ppb in plain candles.

Researchers from Ireland recently noted, “In poorly ventilated rooms, we have observed that concentration of pollutants like formaldehyde reach levels that can cause upper airway irritation”. Formaldehyde has been classified as “carcinogenic to humans” and has been linked to nasopharyngeal cancer and leukemia with high exposure levels.

Polycyclic Aromatic Hydrocarbons (PAHs)

Several polycyclic aromatic hydrocarbons, including naphthalene, anthracene, and pyrene, have been identified in candle emissions. These compounds are products of wax combustion, fragrance chemicals, or dyes used in the candles. PAHs are well-known for their cancer-causing potency, with research indicating they contribute significantly to cancer risk..

Interestingly, benzo[a]pyrene, often used as the marker for PAH exposure in regulatory settings, only contributes about 11% of the total cancer risk from PAHs. The remaining risk comes from other directly emitted PAHs (72%) and their degradation products (17%).

Benzene and Toluene

Paraffin wax candles, in particular, have been found to emit toxic benzene and toluene. Benzene has been linked to leukemia development with long-term, significant exposure. A South Carolina State University study found that melting paraffin wax-based candles emitted these toxic compounds, while soy candles did not.

Factors Influencing Carcinogenic Risk

The potential cancer risk from scented candles varies based on several key factors:

Wax Type

The type of wax used in candles significantly impacts their emissions and potential health risks:

• Paraffin wax: Derived from petroleum waste byproducts, paraffin is the most commonly used wax in mass-produced candles. Research indicates it releases hazardous air pollutants when heated, including carcinogens like benzene and toluene

. Scientists describe paraffin candle soot as most closely resembling diesel vehicle exhaust in chemical composition.

Natural waxes: Soy, beeswax, and other natural waxes appear to produce fewer harmful emissions. Studies suggest soy candles don’t emit the toxic toluene and benzene that paraffin candles do.

Fragrance Components

The artificial fragrances used in scented candles can be problematic. Many contain synthetic chemicals derived from petroleum, with 95% of chemicals in synthetic perfumes and scented candles containing benzene derivatives. These fragrance compounds release additional VOCs when heated.

Ventilation and Duration of Exposure

Poor ventilation significantly increases exposure to potentially carcinogenic compounds. Research shows that in poorly ventilated spaces, pollutant concentrations can reach levels that cause respiratory irritation.

The duration and frequency of exposure also matter. “Frequent consumption of scented candles for quite a long time and their use in inadequately ventilated rooms may increase the chance of developing urothelial cancer”

The Scientific Evidence Linking Scented Candles to Cancer

While direct epidemiological studies specifically linking household scented candle use to increased cancer rates are limited, the scientific evidence for concern comes from:

1. Chemical identification studies: Multiple studies have identified known carcinogens in scented candle emissions
2. Occupational exposure research: Studies of workers with heavy PAH exposure (similar compounds to those in some candle emissions) show substantial risks of lung, skin, and bladder cancer
3. Laboratory analyses: Research demonstrates that burning paraffin wax releases ultrafine soot particles containing carcinogens that can penetrate deep into the lungs and enter the bloodstream
4. Simulation studies: Some researchers have used indoor air modeling to estimate exposure levels. One study found that “the vast majority of the resulting air levels from the scented candles utilized the compared air quality standard to less than 0.5% for workplace-related standards,” suggesting limited risk under normal use conditions.

Health Complaints and Symptoms

Beyond cancer concerns, studies have documented immediate health effects from scented candle exposure. The most common complaints include:

• Vertigo and headaches
• Mucosa irritation
• Respiratory issues
• Watery eyes and sneezing
• Stuffy nose
• Chest tightness
• Dry or irritated throat

These symptoms suggest that scented candles can act as respiratory irritants even with short-term exposure.

Conclusion

While scented candles, particularly those made from paraffin wax with synthetic fragrances, do emit compounds known to be carcinogenic, the actual cancer risk from typical household use remains uncertain. The evidence suggests that risk factors include the type of wax (with paraffin posing greater concerns), the quality and source of fragrance oils, frequency of use, and ventilation.

For those concerned about potential carcinogenic effects, alternatives include:

1. Choosing candles made from natural waxes like soy, beeswax, or vegetable oils
2. Selecting products with essential oil-based scents rather than synthetic fragrances
3. Ensuring proper ventilation when burning any candle
4. Limiting the duration and frequency of candle use
5. Considering alternative methods of home scenting that don’t involve combustion

While more research is needed to quantify the precise cancer risk from household scented candle use, the current evidence warrants a precautionary approach, particularly for individuals with respiratory sensitivities or those concerned about long-term chemical exposure.